Start wearing Ava as soon as you receive it, no matter where you are in your cycle.
If you first start wearing Ava in a cycle where you haven’t yet ovulated (if you’re still in your follicular phase), then Ava will start working immediately to detect your fertile window in real time.
If you first start wearing Ava in a cycle where you have already ovulated (if you’re in your luteal phase), then Ava will use the date of your last period to estimate when your last fertile window occurred. As soon as you enter the date of your next period, Ava will begin detecting your next fertile window using the physiological data it gathers.