Could I be?

I am on the implant Birth control Implanon. My boyfriend and I are madly in love and have already talked about marriage and proposals. He had always came in me. Should I rely on this form of birth control that much? I think it may be too late...swollen sore boobs, day late from starting my period, emotional, acne is starting to go away. (23yo and I still have bad acne until now) could I be Pg? I really need some advice.