“Doctor, I’m pregnant.” The patient said I nodded in response. “But I want to ask you a favor? Help me figure out if this baby is my current boyfriend’s?” “What’s the case? You don’t know yourself?” I thought to myself. “My last period was 2019.8.2, I got passionate with my ex-boyfriend on an impulse on July 25th; and I got together with my current boyfriend on August 14th.” “Oh!” “So now I’m 6 weeks pregnant, whose baby will this be? And the current boyfriend is proposing to me?” The patient looks worried. “How is your usual menstrual cycle? Is it regular?” I asked “Quite regular, 2 days early every month” the patient said. “Can you confirm that August 2 is a normal menstrual period?” I asked again. “I can be sure that it was a menstrual period because it was the right amount and the right time, and besides, the last menstrual period was on June 30th”. Ovulation is the process by which mature eggs are expelled from the ovaries. When a woman is born, there are about 300,000-600,000 follicles on both sides of the ovaries, but during a person’s lifetime, only about 400 follicles mature and the rest degenerate. The process by which a mature follicle ruptures and the egg is expelled from the ovary and falls into the abdominal cavity is called ovulation. Ovulation often occurs about 14 days before the menstrual period. For example, if the patient’s last menstrual period came on August 2nd, then around August 16th would be the time of ovulation. Generally the egg survives in the body for 1-2 days after it is discharged, while the sperm is discharged and survives in the body for 2-3 days, and in a few cases up to 5 days. In the ovulation period before and after 2-3 days each about a total of about 7 days that is easy to get pregnant period, the other time for the safe period. In order to increase the success rate of conception or contraception, the following methods are generally used to monitor ovulation. 1, basal body temperature monitoring basal body temperature refers to the body temperature in the early morning during inactivity, in the pre-ovulatory period has been low, after ovulation that is significantly higher about 0.2 ~ 0.5 ℃, has been continued until the onset of menstruation. biphasic BBT: suggests that there is ovulation, menopausal women or women with ovaries removed do not have a biphasic BBT monophasic: suggests that there may not be ovulation. 2, cervical mucus monitoring in the first half of the menstrual cycle, cervical secretion of mucus, vulva is also very dry. In the first half of the menstrual cycle, the cervix does not secrete mucus and the vulva is very dry. In the first half of the menstrual cycle, the cervix secretes no mucus and the vulva is very dry. Before ovulation occurs, with the emergence of estrogen peak, the cervical mucus becomes thin, transparent, clear, and the amount increases, which is called fertility mucus. 3, test paper method There are test papers on sale to measure ovulation, you can buy to test yourself. Put the test paper in their urine, if the test paper “small window” appears two red lines, indicating that ovulation is imminent. This method requires several consecutive tests. 4, ultrasound imaging monitoring (ultrasound) generally in the menstrual cycle on the 10th day of monitoring, observation of follicle diameter changes, in the four days before ovulation follicle diameter average daily increase of about 3mm, in the follicle before ovulation maturity of about 17 ~ 25mm, ovulation follicles disappeared, continuous monitoring can be seen in the follicle before ovulation continues to grow when the largest follicle disappears, suggesting the occurrence of ovulation. (This method is reliable, but requires continuous monitoring, high cost). 5, ovulation detector This method needs to be purchased for self-testing. In the 2nd day of menstruation to start testing, each time the oral sensor placed on the tongue to use 3 seconds, continued for a few days, the instrument’s screen will indicate ovulation in advance. This method can be used once a day. However, it should be emphasized that: many people think that the safe period of sexual intercourse can not be used without any contraceptive drugs and contraceptive tools, in fact, the “safe period” is not absolutely safe, because the man’s sperm can survive in the female body for 3 to 5 days, and the date of female ovulation may be advanced or lagging behind, so only rely on the safe period of contraception is very unsafe, the correct use of contraceptives or the use of a full range of contraceptive rate to maximize the assurance of contraception. After listening to this popularization, the patient finally stretched her clenched eyebrows, and she didn’t need me to tell her that she knew who the baby’s Dady was. Although I do not approve of the patient’s approach to sex, I am not in a position to kidnap and blame others for “morality”, but as a doctor, I need to emphasize that if you are not prepared for pregnancy, please do not have unprotected sex, because the danger of unwanted pregnancies that lead to abortions is really too much to write home about.