Vaginal lubrication during sex is due to increased secretion of the glands in the vulva. Secretion of those glands can be provoked by local physical stimulation or erotic thoughts. Without the vulva’s secretion, sex would be very painful for both partners. Eventual vaginal discharge due to infection may contribute to excessive vaginal lubrication during sex. You can check if you have some vaginal infection or not. It doesen't seem likely to me that progesteron-tablets can cause your problem.