Anyone had this??

So I'm officially 30 weeks and last night Hubby and I were getting frisky in the tub next thing I noticed I was bleeding, it was bright red and had a bit of stringy discharge that was blood tinged. I figured it was just the position we used caused I felt him really deep in there 🙈 we rinsed off and called it a night. I went to pee and noticed I was still bleeding, dark red now. No cramping, no pain just bleeding. It didn't last long and Dr said it's definitely the position we used. Has anyone had this before? I'm a bit worried don't know if it's valid or not