Sex during the last 7 weeks of pregnancy.

I'm currently 32 weeks and 3 days, this time after sex with my husband he told me ...he couldn't "fit" all the way. Meanwhile I thought he was being super gentle which was great. Afterwards he tells me " It felt like I couldn't fit all the way and I felt something hard, like I shouldn't thrust all the way"

Up until this point I always ask "does everything feel normal down there"?

Is it safe to assume baby's head is down and engaged?

This is my 3rd pregnancy and I have a history of early delivery cause I have a bicornunant uterus.

Should I tell my OB at my next visit this Friday?