Hi There, Would Love Some Feedback. The Past 2 Days

Hi there, would love some feedback. The past 2 days ive been getting stomach pains when i am working out. i am pretty good shape and have not changed the way i exercise in anyway to expect this change (as in i havent increased the amount, so it doesnt make sense that i wouldnt be able to do the exersizes). i thought it was heat exhaustion or dehydration, but ive been drinking fluids like crazy so i dont think it is that. I did have a dehydration episode last tuesday, but then picked back up with exersize on thrusday and saturday and everything was fine. the only other change is that ive stopped smoke weed 1 week ago from today... thoughts?