HELPP

Okay I need help. I have been haveing unprotective sex since 04-27-2017. I am also not on birth control. My husband has pulled out almost every time we have had sex. I felt like vomiting yesterday also very very dizzy and I feel butterfly's in my belly. I am also always tired. I have taken test, they all came negnative. It's weird because for like a split second they are positive but then they turn negative. My periods don't last long and the last time I had one was on the June 11th-13th very very light. And sex is an everyday thing, I'm so confused. Should I go to the doctor and get a blood test? Or should I wait to take another test... please help!!