Ovulation

Sa

How accurate is this app's <a href="https://play.google.com/store/apps/details?id=com.glow.android">ovulation calendar</a>? I just want to know if anyone has gotten pregnant on a supposedly safe day or if the data is actually correct! Not trashing the app, I'd just like to know! Also, how do I know when I'm ovulating?? Symptoms?? Length?? What exactly goes on?? Thanks 💚