Dry as the desert

I was suppose to get my period 3 days ago, and it doesn’t seem like she is coming anytime soon but I am like CRAZY horny, and I’m usually super wet all the time, last night my boyfriend and I went to do it and no matter what he did or how turned on I was, I was so dry, like so dry that lube barley did anything, and we are having the same issue tonight! I’m super hydrated, I drink a crazy amount of water. Why could cause this?