Help Im overthinking

Okay soooo I was on birth control for 3 months and just got off from it on the third month. However, I had unprotected sex 2 weeks ago (he didn’t finish) and took a plan b. Now, my period is late. One <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period app</a> says I’m late by 4 days and another says I’m late by 1. But there is a bigger problem. I had unprotected sex and he finished inside of me for the first time ever. I took a plan b immediately. I’m just scared that I’ll be running a huge risk of getting pregnant if I’m not sure if I’m ovoluating. Also, what are some good tips to do after to lower the risk of pregnancy? Is there a certain way I need to clean up? Do I need to drink something? How do I know if I’m ovulating? Ps. My discharge has been like white cottage cheese but not too much like it. It just comes up in tiny balls.