Spotting PLEASE GIVE ADVICE

I started having sex. Me and my boyfriend were having but all he did was pre cum in me. I was spotting all last week, well I think it was spotting. I took two pregnancy test and they both turned out negative. Is spotting normal or was that my period? Im going to be put on birth control next week. Will they tell me then? Like. I don't know if im supposed to expect my period this month or if the spotting was it. It wasn't very heavy but it was heavy enough for me to wear a tampon all week long. But the blood was kind of brown.. I don't know, help?