TMI - Miscarriage or Period?

I hadn’t gotten my period in 2+ months but because I have PCOS sometimes my period would be irregular/missed, my last pregnancy test was negative about a month ago. Today I went to the bathroom and this came out. I’m not used to having such bad cramps or blood clots as my periods are much lighter now than they used to be (back in HS they were much heavier) when on birth control. So I’m not sure what to think, is it just a period very late? Chemical pregnancy after effects? Anyone else experience something similar?