Hi littlemisstery
I have the same thing! Are you on the pill? My doc initially thought that it was due to not taking a pill to have a period i.e. the body doesnt like losing the hormones and reacts with night sweats. This makes sense cos the sweats happen during my period.
I have also been for loads of tests i.e. thyroid, hormonal, HIV, the works and everything is normal! My doc suggested that I come off the pill so she monitored my hormones after I had been off it for a few months and the only issue was slightly low estrogen. The estrogen wasnt low enough for her to worry. She thinks that it's just because I have been on the pill for a few years so my hormones are re-adjusting. BTW I am 29.
The doc has now suggested that I stay off the pill a little longer so she can keep an eye on my hormones. But my skin has badly broke out so I am going back on the pill. My new plan is not to have a period at all i.e. keep taking the hormones, and see if the sweats re-appear. Oh, since coming off the pill (4 months now) I havent had many sweats at all. I honestly think it has something to do with the pill.
Keep me posted on your progress!