The three processes that occur during menstrual cycle are as follows:
1. In the early phase of menstrual cycle, a single ovum (egg) is produced by one of the ovaries. This process is called ovulation.
2. Ovulation is followed by the thickening of the uterus wall which is essential for the reception of egg.
3. In case fertilization does not occur, the lining of the uterus as well as the egg are shed, which is accompanied by bleeding. This period is called menstrual period.