okay so i'm 19 right now. and even since i started my period i've always been luberciated. till recently.. i'm worried because even since i could remember i've always been wet. a couple of weeks ago me and boyfriend went on a trip, we had sex every night and i was perfectly luberciated all in my natural way. And now that we got back from the trip, we tried having sex but i'm dry. should i be concerned? i know i can use lube to help. but i just want to know why this is happening...