What would cause this pain?!!!

I got a really strong positive opk when I got home at 5pm. We did the deed around 7pm.

Laying down at 9pm and I have the worst pain I have ever felt but it only last about 1-2 minutes. Almost enough to put me in tears. Just felt like pressure in my pelvis and anus, I had to stay still because moving made it hurt more.

Update: no pain during sex. Just a couple hours after not sure why the pain would have happened.