Boyfriend feeling my cervix

I had mentioned on here days ago that my cervix felt soft an kinda swollen well last night after sex my boyfriend said he could feel it with his penis an that it felt open like a donut he's NEVER felt my cervix with his penis like that so a bit concerning he didn't know what it was he asked what he was hitting I said it could have been the baby's head😂 he said no it felt like this he just made a circle with his fingers an said there was a hole in the middle I'm almost 31 weeks baby has been active baby seems fine but I'm not real clear on this cervix thing when does it start opening an moving to get ready for labor I go to the doctor tomorrow but it's rotation an not the doctor I normally see should I mention this to the doctor