Cramping after sex

A few times after I have had sex with my boyfriend, I get extreme cramping where I cannot move. I have gotten very nauseous and sometimes it lasts about an hour. The other night I got cramps that weren't as severe, but I know its all related. This has happened about four times all together. I read that endometriosis can be caused by ghonnorea or chlamydia, but I was just tested for STD's and have neither.
I am making an apt. with my gyno tomorrow, but what could this be??
I'm very scared

[Pres0081]

Endometriosis is not caused by ANY STD. Just thought I'd point that out.

[Kara_robbie]

I was just diagnose with endometriosis and painful sex is one of my symptoms. Not sure about the severe cramping though...defiantly should be looked into.

[leelee105]

thanks for responding! the pain during/after sex felt like period cramps times 100000. is that how you were feeling?

[Kara_robbie]

No I dont think they are that bad for me but sometimes it caused me to spot and I would ache inside for awhile so finally I went to the dr because my periods were getting pretty painful and I had lots of clots. I am also having trouble conceiving and my dr told me that is also a symptom of endo. So that is why I am taking Clomid now....in an attempt to get pregnant.