Vacation means menstruation. Taking progesterone on the first day of menstruation usually does not stop menstruation, it is not suitable for taking progesterone during menstruation, and taking progesterone should be guided by a doctor. Taking progesterone on the first day of menstruation will not stop menstruation because the progesterone preparations do not contain particularly high levels of progesterone, and taking the drug may not necessarily stop the endometrium from shedding immediately. However, it may cause a decrease in the amount of menstrual blood during menstruation, or prolong the menstrual period, bringing about abnormalities such as irregular vaginal bleeding. Progesterone is a natural progesterone secreted by the corpus luteum of the ovary that increases the thickness of the endometrium. If you want to take progesterone, you should avoid the menstrual period and choose to take progesterone before your period or at other times. Women are advised to take progesterone always under the supervision of a doctor. Abnormalities after taking progesterone on the first day of menstruation should be treated promptly.