Could I be pregnant?

Me and my bf just had sex today, and my <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period app</a> says I’m in my ovulation week. It was unprotected, but he pulled out pretty early. I know there is precum tho, and that can get you pregnant. It’s been a week since we had sex before today, and he’s not cum anytime in between then and now and I don’t know if that changes the risk of sperm in precum or not.

Should I take plan B just to be safe?