There are a bunch of reasons it could have been painful. Having sex with different people is different. Also, during ovulation, you can be a little swollen, causing pain and bleeding. The discharge after your period is pretty normal. Nothing sounds too out of sorts.
However, I DEFINITELY recommend at least giving your gyno's office a call. The nurses can be incredibly helpful at explaining what you want should be worried about and what you shouldn't.
Hello,
The bloating and feeling sensation along with nausea can be due to gastritis after the hangover. Take some OTC antacid like Mylanta.You can also take zantac(ranitidine)or prilosec(omeprazole).These will help. Also keep your fluid electrolyte balance optimum by drinking lots of fluids.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.