QUESTION: So I started taking the pill while I was on my period. 5 days later I had unprotected sex…

QUESTION: So I started taking the pill while I was on my period. 5 days later I had unprotected sex with my boyfriend. I was supposed to start my period last week. I've taken two tests and they came back negative. A couple days ago I had brownish spotting. Is my period out of whack due to the birth control or could I be pregnant? I'm 3 months pp..