possible pregnancy odd symptoms negative hpg help?


ok ladies I'm having really bad pain near and around my belly button and in back that feel like contractions. the pain has been causing severe nausea it's worse if I stand or walk. I have been nauseated for 3 months or so. I'm getting heart burn which doesn't happen since I'm on 80 mg Prilosec. I've had sore breasts and even gained weight for no reason. this month my period started 2 days early ended 3 days early and was lighter than normal. I took hpt this afternoon was negative. is it possible to be pregnant and have no clue? these contractions are driving me nuts. thank you