Ladies with multiples!!

Nakita • 30 years old, Married Baby 1- June 2015, Baby 2- October 2016, Baby 3- March 2018! Baby 4 October 2019
This is my second baby. With my first, my boyfriend and I had sex right up until the day she was born. This time we don't have sex as often, but we still do often enough. Well this morning we were doing the deed and he said he thinks I'm further along(my dr also thinks I am) because he said he can't tell if it's a head but he said my down there area(inside) has changed, and it's more so like it was at the very end of my first pregnancy. Do you think he's crazy ahaha or has any of you experienced this as well!?