When I was 9 weeks I bled after sex then they try to convince me it was normal I had an early scan and everything was fine im now 16 weeks with a health baby so I wouldn't worry docs say sex can.cause you to have a small bleed
It's not uncommon following sex but I know how nerve racking that can be. What is probably the smallest amount of blood mixed with other fluids and makes it seem 25676247 times worse too, kinda like bleeding from your gums, or biting your tongue. Anyway, when is your next appointment?!?! From experience if you call they'll likely tell you it was the sex... Just as paps have a way of making you spot. But really, do what makes you comfortable.. if that's a trip to the clinic to check babies heart beat, then so be it. Good luck.
I've heard of that happening and in the case I know, there wasn't anything wrong, but just to be on the safe side I would call your OB just to check. My best friend had it happen after sex and her baby was fine. Don't stress too much, but definitely go get checked out.