Asking for a friend....for real lol

So my coworker told me this story and I’m stumped.

Her and her husband were having sex the other night (not rough and she always lays a towel down before hand) and when he pulled out after finishing the towel was completely soaked in blood. It soaked through the towel onto her sheets and she noticed a dime sized blood clot. She says during sex she felt a very sharp pain shoot yo her left side hip and back.

She asked her OBGYN if it was normal because obviously she’s concerned but they said it was normal and to only be concerned if it starts happening more often.

Y’all think this is normal???

We work in a family dr office and none of us think it’s normal lol