Intercourse???

I recently turned 30 which really has nothing to do with this question but this has happened to me for years and not sure if it has always been like this but I've seen something about women going through menopause and this happening ect and thats not the case with me but.. When me and my boyfriend have sex I am really wet to start out with but just as soon as I orgasm I am dry as all get out. We use lube when needed but I don't get it. I've always thought that once you orgasm you are suppose to be wetter. Does this happen to anyone else or is it just me and is it normal?