Reasons for spotting/cramping mid-cycle?

Molly

First day of last period was 4/14. Last night and throughout the day have had very light spotting. This evening feeling crampy, as if my period is coming again in the next 1-2 days. Could there be any other reason for this? I have PCOS, so unlikely related to ovulation, because I historically have a 30-32 day cycle without ovulating.