When my oldest sister first started having kids, I used to play a game with myself of guessing their birth date, weight, and length the day she told me she was pregnant.
First pregnancy, the due date was the 20th of a month, I guessed the 25th of same month, kid ended up born on the 27th (don't remember the weight/length I guessed, but I was only slightly off with that as well).
Second pregnancy, the due date was the 26th of a month, guessed the 13th of the month after (so overdue), kid ended up being born the exact day I thought (don't remember the weight/length, but I was even less off than the first one).
Third pregnancy, the due date was the 5th of a month.... and I didn't have any sort of guess. No feeling. Nothing. Felt utterly and completely disconnected. No date felt "right". My sister ended up miscarrying about two weeks later.
I stopped playing the game after that.