Hello, I have gone through your query and understood the concern. If you have already had your natural period with all your symptoms persisting, then your cramps and diarrhea are more likely to be related to some gastro-intestinal cause. Please see a physician and get proper treatment. If you wish to exclude/confirm pregnancy, you can go for the estimation of the serum beta-hCG titres. If negative, you are more likely to have an intestinal cause that needs to be treated. Soreness of the nipples can also be due to tight supports, sweat and lack of ventilation. Hope this helps.