I feel pain during sex, & nausea with bloating right after nearly every time we get physical. my periods are short (my last was 1.5 days long) but progressively more painful. my bowels are also really affected before/while pmsing. what could this be?

Pain during sex and painful periods should be assessed by a gynecologist to see if there is a problem. Since you are PMS-ing I assume you are not on birth control pills. Since you are interacting in a sexual physical way, it would likely relieve some of your anxiety and possibly many of your symptoms if you used effective birth control. Anxiety around sex can give many symptoms.

If it occurs daily or off and it could be STD-be pelvic inflammatory disease. Most likely you have If you symptoms are lasting months or longer or you could have an ovary and cyst or endometriosis see a OB/GYN for diagnosis and treatment