Confused

The past few days I’ve been having really bad heartburn. I’ve never ever had this feeling before and at first I was really scared. I’m just a little confused as to why all of the sudden I’m having this problem. Me and my husband are sexually active and do it pretty regularly. This past week and a half I’ve also been having a pain in my uterine area and it’s not like a period cramp at all it’s much shorter and been experiencing dizziness. I’m about a week away from starting my period. Is heartburn a normal symptom of early pregnancy? I haven’t been really nauseous, sick, or had diarrhea like most people do. I feel that it’s too early to take a test just yet and I haven’t had the tale tell signs. So I’m just all around confused and need advice.