Lol intruders! Made me laugh! Just tell him not to go so deep . You're sensitive :) it's very normal and nothing to worry about. Just mention it at the next appointment :)
It's probably slight uterine contractIons that can be caused by orgasm.
I worry about this too but I think you'll be okay...lol
Oh, and that happens to me to, my doctor said it was fine.
There's no guy long enough to touch your baby ::)