Low cervix to High within days?

Amanda
Hello Ladies,
Af is due next Friday so naturally my cervix would start to move down and become firm. For the past two days this is how it's felt, but when I checked it this morning I couldn't find my cervix!?! I've reached and squatted down as much as I could but I still can't find it! Why would it have been so low for two days and then all of a sudden move up?