Cramping after sex on "peak" day?

Question

I took a +OPK yesterday, afterwards we BD'd. 
Immediately after he came, I got the most intense cramps of my life. Almost felt like contractions! Has this happened to anyone else? I have never done this before & I have 2 children. 
I had to elevate my butt on a pillow, and just getting the pillow under me nearly had me in tears. I had to go take a bath 30 min afterwards.

Answer

I’ve actually had this happen on and off for about two and a half years. I’ve gotten a trans-vaginal ultrasound and an abdominal ultrasound, and they see nothing. Urine samples have been taken, nothing. My only other choice is to be tested for endometriosis, but I haven’t decided if I’m going to or not. It was so bad one time, I couldn’t stand up straight, and had to take a warm bath. Is this the first time it has happened?

Cramping after sex on "peak" day?

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