What does this mean

8 days before my period I started spotting, ive been spotting for about 4 days now nothing major just some light spotting throughout the day. I’m on the pill brevinor and this is only my second cycle taking it. Last time i had sex was 23rd of March and i got my period as normal the cycle after I had sex. Why could I be spotting?

(I have some mild cramps same type of cramps I’d get if I was starting my period & tender breasts)