Missed Period 😩

Is it normal to miss your period on Birth Control? I'm sexually active and I don't use protection and my period was supposed to come on Tuesday and still nothing. I had some mild to light spotting a week before my period. I took two pregnancy test and they came back negative. I don't have any pregnancy symptoms, but I can still be pregnant. And when my period was supposed to come I got some light pink and a little bit of brown discharge. Any suggestions on what's going on with my body????? 😭😭