Hi. November 16 I Started My Period. Then It Came

Hi. November 16 I started my period. Then it came again November 26th & I havent gotten it in december and still havent gotten it. I been sleeping ALOT, my breasts have been sore, i noticed i pee more than usual sometimes. Today i felt bloated & 2 days ago I got a few cramps on my side. Idk if its my period coming or not. Im alo on Birth control (the implant in my arm) so i doubt it. But i heard of a few people on the same birth control who managed to get pregnant. Help please.