PCOS with pregnancy

So I have PCOS (poly cystic ovarian syndrome) which is the most common thing that makes women infertile because It makes ovulation abnormal. So for the past year I have had normal periods every month on time. My fiancé and I are sexually actively and I haven't had my period in 3 months and had many prego symptoms. I took two pregnancy tests and both were negative (although people with PCOS usually have to have a blood test or ultrasound to show up) Two days ago I started bleeding medium to light at first and now I have very little bleeding almost none to wear I don't need a tampon. Could I be pregnant or is it just my PCOS messing with my body?