What is wrong with me my body isnt working.

For the last 3 days in a row i cant get wet! I want to have sex but it doesnt work for nothing. Even lube doesnt help. I normally dont have this problem and i understand that pregnancy changes stuff (im 27 weeks) but now SO is hurt, im frusterated and confused and its just a big mess. Does anyone have any clue what's going on or how to help? Has it happened to anyone?