I've had this in my arm since last year in September. I've had the same boyfriend for the past 4 years and my mom decided to get me on birth control. I'm only in high school an she knows I have sex. He has came in me before and the birth control has been working great but now this last time he came in me (few weeks ago ) I didn't get my period at the end of the month , that normally goes into the following month but I didn't and I'm scared... I have no one to talk to. Can I get pregnant if its worked before ?