SOS WORRIED

Hi everyone, im posting because I’m scared I might be pregnant. I never missed a pill and my boyfriend never cums in me even though I’m on birth control. The thing is, I got my period two days ago and there was barely any blood and today there’s almost nothing and this never happened before even though I’ve been on birth control for 8 months. Could this be a pregnancy scare?! I know the chances of me actually being pregnant are so low but why else would this happen?