Need advice!

So I'm 4 days after ovulation and my husband and I have been TTC, i'm in the middle of cycles and last night after hubby and I did BD, I started lightly bleeding, I thought maybe it was just from friction from sex or something, but it hasn't stopped since. I think it's too early for implantation bleeding, and it would be two weeks early if this is AF. Don't know what else it could be, very frustrated and upset! This ever happen to anyone before?