After taking drospirenone tablets for 10 days, menstruation usually occurs 3-7 days after stopping the medication. Didrogestrel tablets are a progestin, or progesterone, that can be used for the treatment of irregular menstruation, secondary amenorrhea, and functional uterine bleeding due to endogenous progesterone deficiency. The medication is usually started on days 11-25 of the menstrual cycle, twice daily. When the drug is discontinued after 10 days, the endometrium will shed due to the decrease in exogenous progesterone levels, resulting in withdrawal vaginal bleeding. If the endometrium is lower than 8mm before taking the medication, the effect of regulating menstruation is usually not achieved by taking didrogestrel, and if you continue to take didrogestrel tablets, you will not have menstruation. In addition, patients need to undergo ultrasound examination and hormone level examination to clarify the diagnosis before taking drospirenone for irregular menstruation. And the amount of menstruation is usually more after stopping the medication, which is normal and patients do not need to be overly nervous.