birth control working?

i’m on birth control (setlakin), which allows me to skip my period for three months at a time. this is my first pack (used to be on it before but stopped for a bit and went back on) and i’m on the second month, but i’ve noticed bleeding. since i still have another month since i’m supposed to get my period, does this mean it’s not working? my boyfriend cums inside btw, always has and it’s never failed