Bleeding 7 hours after sex while pregnant

I am 21 weeks pregnant and last night me and husband had sex, I woke up 7 hours later to find I had light pink bleeding, and a small clot, after the small clot I’ve had no bleeding since, I’ve checked the baby heartbeat on the fetal doppler and it seems to be going well, I just haven’t felt him move as much and it’s worrying me, I have a scheduled appointment with my OB tomorrow, but I was just wondering if anyone else has experienced this? We had a miscarriage earlier this year so it’s making me nervous..