Cramping prego

So I’m 6 days late and I took a test 3 days ago came out negative and I have been having like stomach pains or cramps and idk if it’s my period coming or if I’m pregnant. Do u get pains like that when ur pregnate? Because the first time I go prego my boobs hurt really bad but I didn’t have the baby, and this time they hurt really bad and my veins are popping out big time. I also want to loose weight so I’m running and doing exercises so if I’m prego I wanna make sure I’m cautious of what I’m doing