I am experiencing irregular periods and I am leaving for my first vacation on Sunday. Since my period is already 3 days late and I experience extreme discomfort with menstruation due to endometriosis my doctor has prescribed medroxyproges 10mg 3x a day for a week to prolong the onset of my period while I am away. I have worked extremely hard the past 3 months to lose weight and I worry about gaining weight while taking the medroxyproges, even if it is for the week. Is weight gain likely to happen in a week?