Spotting after sex only at certain times of cycle?

So for 3 cycles now I’ve spotted after sex during only my luteal phase. It is only a small amount of bright red blood mixed with other fluids and it doesn’t last, just the one time after sex. I also have weird cramping more throughout my luteal phase, which I guess is just different since my miscarriage 3 months ago, since I never cramped before. Has anyone had this before? Was everything ok? Were you still able to conceive? I’m planning an appointment with my OBGYN but waiting to hear back and am super paranoid that I can’t get pregnant again after my miscarriage in February since we haven’t conceived yet. Any advice welcome, thanks.