Is Spotting,nausea,dizziness Sign Of Pregnancy?

I lost my virginity in december and the day ilost it was the last day of my period for that month and also we didn't use a condom. In january i had something like a period but it was lighter and shorter and didnt really feel like a normal period. So i took a pregnancy test a couple of days ago and it was negative But something still doesnt feel right. I still have all the symptoms of being pregnant: nausea, tired all the time, drizziness, lower back pain, eatin everything in sight and even my stomach feels funny and kinda heavy at times and tight so what should i do?????