HELP! Vaginal problems

So my boyfriend and I have sex maybe 2-3 times a week. We always go all out and I never had a problem getting aroused but the last few times I have been ready to jump on him and when he gets ready to put his penis in, my vagina is so dry. What is the deal with that. I never had this problem before. I feel like we have been using a lot of excess lube & I get kind of embarrassed. Are my brain and vagina not in sync? What should I do?