First month on birth control. Should've started my period yesterday, today I am

[Jessica]

spotting. Could I be pregnant? I started birth control this month for the first time ever. My doctor told me I should start taking it the first day of my period. I waited 14 days exactly to start having sex but since then my boyfriend and I have really taken advantage of the no condom benefit birth control has given us. I take my birth control everyday at the same time. However, I was 3 hours late one day because my phone died and it slipped my mind (I have an alarm set). My cycle usually comes every 25 days, which would have been yesterday. I'm 5 days into my white pills now. And today I started spotting. It's very light and brown. I have never spotted like this before my period. Only after. Is it possible that my birth control has failed and I am experiencing implantation bleeding? Or is it possible that the birth control is actually messing up my period? I'm scared I could be pregnant. If I take a pregnancy test should I wait longer? I am technically a day late for my period but what if I am actually experiencing implantation bleeding? Please help!