Menstruation is on April 3rd, so the expected menstrual cycle is 30 days, and the number of days in each month is the same. Based on the menstrual cycle, the time of the next menstruation can be calculated (called the 14 days before the next menstruation in the cycle), which is the ovulation period.

If your menstrual period is on April 3rd, then your next menstrual period will be on May 3rd. In other words, ovulation will be around May 16th. During this period, the egg in the female body is waiting to meet the sperm, form a fertilized egg, and implant in the bed.

During ovulation, a woman's body may experience a series of changes, such as increased body temperature, increased appetite, breast swelling and pain, etc. These changes may indicate that a woman is entering pregnancy.

If you are planning to become pregnant, it is best to start taking some measures at this time, such as using condoms or oral emergency contraceptive pills. If you're not ready to get pregnant, you can choose to have sex during non-safe periods, but you still need to take steps to protect yourself and your partner's health.