Low progesterone post partum

Hey all, I've had 2 children, my youngest is 13 months. Has anyone with a kid noticed that their cycle is different post partum? I still have a regular cycle at 32 days and ovulate at 17 or 18, but I spot at 9dpo nearly every cycle. I dont get AF flow tol 14 or 14 dpo but I believe my progesterone is low and so my luteal phase is short....

I'm worried if I try to conceive again this will be a problem, and because I'm getting older.