Could it be my birth control delaying my period?

Okay, so my periods are kind of odd. I had a baby in July of last year. I got my period for August at the end of the month. But for my period for September I got my period at the beginning of November. And I got my period for November at the beginning of December! My periods are really off and I don’t understand why. I’ve been on birth control before. But I wasn’t on birth control for the first 2 weeks of January. And I had sex maybe 4 times during the two weeks. I had a period at the beginning of January, so would that period count for January? Because I got on the 3 month shot birth control on January 27 and I haven’t gotten my period at all. Could it be my birth control? I don’t have signs of pregnancy. I am bloated, but could that be my birth control too?