Weird brown periods while breastfeeding...

Lisa
Hi all :)
LO is 9mo, breastfeeding, introduced solids at 5m. Period returned at about 4m. I have PCOS. Cycles used to be 33 days, after bub seem to be 35 days except last month was 38 days and I bled brown for about 2 weeks. This month back down to 34 days but bleeding brown again? Wondering if it's the breastfeeding or if it could be PCOS? Anyone else?