Please help me! :(

Ok I'm 18 and I had protected sex early in June. I got my period at the right time in July, but I was sick. Like I was having diarrhea and nausea. It was also a bit shorter than average. Now I've had regular periods for years and I'm on lo lo estrogen. And due to mouth surgery I ended up missing 7 pills out of the pack and got my period 2 weeks early in august.

Since Tuesday I have been waking up with stomach pain, nausea, and having to go poop. It last for a while but will go away once I start doing something. But it comes back when I'm trying to go to bed