How long do blood clots last after having a baby?

I had my daughter 8 months ago, and when I am on my period I still have pretty descent size blood clots. I'd say they are the size of a cashew. I get stomach pain when I'm on my period, similar to cramps, but they're higher up on my stomach. I sometimes get light headed on my period. So I'm trying to find out if having blood clots this size is normal or if it isn't normal.