The endometrium is in the proliferative phase or has just entered the secretory phase 7 days after menstruation. For women, menstruation usually lasts 3~7 days, and the 7th day after menstruation is usually in the 10th~14th day of the menstrual cycle, when the follicles may be in the stage of continuous growth or have been discharged, so the endometrium will be in the late proliferative or early secretory stage under the action of estrogen and progesterone. If you want to determine the exact period, you can base your judgment on body temperature changes and estrogen and progesterone levels if necessary. As the corpus luteum will be formed after the follicle is discharged to produce progesterone, which can act on the body’s thermoregulatory center, the body temperature of a woman in the secretory phase will increase by 0.2 to 0.3 degrees Celsius; at the same time, the level of progesterone will also gradually increase.