Period talk and birth control


So I got the green light last Tuesday from my doctor, that I can stop taking my birth control so my husband and I can start trying for a baby again. Well Sunday I started to bleed light pink witch I thought I was spotting cause I normally do. But on Monday it started to get darker. This isn't my period because my period started on the 13 and ended on the 18th. So I dont know if its because I stopped taking the birth control or if my pcos has something to do with it. If anyone could help me out that would be great.