Ava Black Friday
Ava Black Friday


Pregnancy Symptoms—Week 1 (What Will I Feel?)

pregnancy symptoms week 1

Even though it sounds impossible, in week one of your pregnancy, you’re not pregnant at all! Doctors count the first day of your last menstrual period as the beginning of your pregnancy, even though there’s definitely nothing growing in your belly (except maybe period cramps).

Because it’s so hard to pinpoint the exact date of ovulation or conception, but usually pretty easy for women to remember the first day of their period, doctors use this metric to calculate your due date. You won’t actually conceive your baby until week two or three (depending on your unique cycle), so you definitely aren’t feeling any early pregnancy symptoms yet. 

(But if you’re interested in tracking your pregnancy week by week—Ava can help.)

How big is my baby?

Baby’s Length: 0.00 in.

Baby’s Weight: 0.00 oz.

Your baby is still an egg safely ensconced in a follicle in your ovary, and the other half of the necessary DNA is in a sperm cell that might not even exist yet.

woman in bed

How is my baby developing?

During week one, the baby doesn’t exist yet! While you’re not technically pregnant, more women know the date of their last period than their ovulation date, so counting from the last menstrual period provides a more consistent way to calculate due dates. Still, consider prepping yourself for conception by reducing your stress, getting enough sleep, taking a prenatal vitamin, and building up healthy habits (and cutting less-healthy ones).

What’s happening in my body?

This week, you have your period. You might not know it yet, but this is your last one for a while. During this time, you’re shedding the uterine lining that developed last month. While this may be unpleasant for some women (pass the chocolate and hot water bottle), a lot of exciting things are happening in your body. This week, two important pregnancy hormones, follicle stimulating hormone (FSH) and luteinizing hormone (LH), begin to stimulate the development of several fluid-filled pockets in your ovaries called follicles. Each follicle contains an egg. One of these follicles will eventually become dominant and release a mature egg. About 40 weeks from now, that egg will be your baby!

The symptoms you’re experiencing are ones you are probably pretty familiar with, like:

  • Vaginal bleeding. This is your body shedding last month’s uterine lining, including your unfertilized egg.
  • Bloating. The fluctuating levels of progesterone and estrogen in your body can result in a bloated belly both before and during your period. Stretchy pants are your friend.
  • Cravings. Some people want salt. Others want sweet. Some people want both (no judgment). Hormones are the culprit here, too.
  • Mood swings. If you’re laughing one minute, crying the next, and tetchy with your partner, blame the (surprise) hormones again. “It’s not me, it’s the hormones,” works wonders, especially if you feed the beast a little of whatever it is you are craving.
  • Headaches. Guess what’s to blame for the menstrual migraines you may have? If you said hormones, you nailed it in one.
  • Fatigue. Although your hormones may not specifically be responsible for making you feel tired, they do influence things that can lead to exhaustion. If you’re soothing yourself with too much sugar, the resulting crash can add to the tiredness. So can the poor sleep that sometimes comes from pain, discomfort, or waking up in the night.
  • Lower back pain and/or cramps. To release the uterine lining, your uterus contracts. For many, this causes your back and abdomen to ache. Put your feet up, grab a hot water bottle and your OTC painkiller of choice, and wait for the worst to pass.

Remember, even once your period is over, you probably won’t experience the first signs of pregnancy until you miss your next period. Still, some very early symptoms that may appear in the next few weeks include breast tenderness, fatigue, the frequent urge to pee, and nausea.

How should I be taking care of myself?

1. Starting taking prenatal vitamins

If you’re not taking one already, start taking a prenatal vitamin that includes at least 400 micrograms of folic acid. Taking folate before conception has been shown to reduce the risk of neural tube defects dramatically. Remember, most women have no idea they’re pregnant in the first few weeks, but the baby is still growing rapidly. Neural tube defects most frequently occur during those first few weeks.

2. Cut out unhealthy habits

If you’re trying to get pregnant, now is a good time to stop unhealthy habits like drinking, smoking, and taking any illegal or recreational drugs. Since your body is about to create a whole new human, it’s important to take care of yourself. If you dig around, you’ll find that the guidelines regarding what’s safe to consume during pregnancy tend to vary from source to source—and definitely from country to country. For example, all pregnancy organization in the United States say that no amount of alcohol is safe during pregnancy, but similar organizations in other countries say that occasional drinking is completely fine. So which is it?

And in the case of caffeine, some doctors will say you should completely abstain while pregnant. But others recommend no more than 200 milligrams per day. And still others say that up to 300 milligrams per day are fine. Whose advice should you take?

The reason for the disparity is that there is a wide variation in the quality of medical research on this topic. If you think about it, the reasons are obvious. Who could possibly conduct an ethical study that examines how five glasses of wine per day affect an unborn fetus?

But how much caffeine is really okay?

According to Emily Oster, who is a professor of Economics at Brown University and the author of Expecting Better: Why the Conventional Pregnancy Wisdom is Wrong, and What You Really Need to Know, pregnant women should feel comfortable with both caffeine and alcohol in moderation. Emily studied all of the public research herself and arrived that the conclusion that most of the official recommendations are overly cautious. She contends that up to one drink a day in the second and third trimesters is safe (and a couple of drinks in the first). In fact, for the most part, studies show that there are no adverse effects on babies at levels even higher than this.

What about alcohol, how much is safe?

When it comes to alcohol, there is no doubt that heavy drinking is harmful to your baby. (And for you!) Multiple studies have shown that binge drinking (having more than 5 drinks at a time) during the second or third trimesters of pregnancy increases the chances of your baby having cognitive problems, such as language delays. One example of these studies is this one from 2009 that was published in the medical journal, Pediatrics. When binge drinking happens in the first trimester, it can even cause physical deformities. But the impact of binge drinking is not the same as that of occasional, responsible drinking, and here is where the topic becomes a bit more tricky.  

When Emily analyzed the data, she found that there was no indication that light drinking (a glass of wine per day) negatively impacts the baby. However, it’s important to note that one drink means one drink. The NIH measures one drink as:

  • 12 ounces of regular beer, which is usually about 5% alcohol
  • 5 ounces of wine, which is typically about 12% alcohol
  • 1.5 ounces of distilled spirits, which is about 40% alcohol

Other things to consider

If you’re thinking about pregnancy, you’ve probably already heard about prenatal vitamins—after all, you’re still in the pre-pregnancy prenatal phase. Before taking prenatal vitamins, though, it’s important to understand what they do and why you might need to supplement the vitamins you’re getting from the food you eat. If you have concerns or want to know how vitamins might interfere with other medications you’re taking (which is definitely possible), make an appointment to talk to your doctor.

For some women, weight can play a significant role in the likelihood of becoming pregnant. Although the Body Mass Index (BMI) may not tell the whole story, women with a BMI between below 19 or above 24 may have more difficulty getting pregnant. In both cases, weight can influence ovulation, and if you don’t ovulate, there’s no egg for the sperm to fertilize. A recent study found that pre-pregnancy obesity is associated with a higher risk of excessive gestational weight gain, leading to maternal complications and a higher incidence of cesarean sections.

  • Hopefully, you’ve been tracking your cycle to figure out your most fertile days. A wearable like Ava can really help with this! If you’re familiar with your ovulation cycle, know that the best time to have sex is two days before you release an egg. If you’re not exactly sure, it’s best to have sex every two days instead of every day.
  • If you haven’t done so already, now’s a good time to sit down with your partner and create a family health history, including any genetic or chromosomal disorders you’re aware of. Forewarned is forearmed, as they say.
  • If you’re planning to conceive, it’s always good to talk to your doctor first. They’ll be able to make sure any medications you’re taking are safe.

This Week’s FAQs

How many weeks pregnant am I?

When is the best time to get pregnant?

Folic Acid: When Should I Start Taking It?

Implantation Calculator: When Did It Happen?

Genetic Counseling: Can It Help When You’re Trying to Conceive?

View sources

Binge pattern of alcohol consumption during pregnancy and childhood mental health outcomes: longitudinal population-based study.

Prepregnancy obesity status and risks on pregnancy outcomes in Shanghai: A prospective cohort study.

Jackie Ashton

Jackie Ashton is a science writer for Ava, with a decade of experience in journalism—interpreting clinical studies and research papers for outlets like The New York Times and The Washington Post.

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