Spotting for a month?!

Hey girls, I recently lost around 32lbs in the last 3-4 months. I have had pcos since 16, I had a miscarriage at 24, and obviously wanted to ttc again, but I took a break to lose weight. I have always had irregular periods. Having one to maybe two a year. Now since I have lost some weight I have been spotting for over a month! Any ideas what this could be?! Any advice? Thanks in advance!