Brownish discharge?

So I got on birth control about 2 weeks ago. About 2 days ago I started to finger myself, and then a lot of blood came out. So what that meant to me was that I guess I was on my period so a day later I saw that there was no blood. So yesturday I had protected sex with my bf and I started bleeding a lot.... that day I found that I had a brown discharge from the blood being old and its still going on until this day... what does this mean? Is it normal??