October refers to the month of gestation, not necessarily 10 months, but actually more than 9 months according to the Gregorian calendar. The current medical method of 10 months of pregnancy is mainly to facilitate the calculation, specifically the female menstrual cycle is fixed for 28 days, that is, 28 days as a gestation month, the entire pregnancy a total of 40 weeks, the full-term pregnancy total 280 days, that is, 10 gestation months. According to the calculation method of the Gregorian calendar, 1 month may have 30 or 31 days, February may be 28 or 29 days, then 280 days that is only 9 more months. For the calculation of the expected date of delivery, pregnant women with regular menstrual cycles start counting from the first day of the last menstrual period, the month minus 3 or plus 9, and the day plus 7 is the expected date of delivery; pregnant women with irregular menstrual cycles can infer the number of days of pregnancy by looking at the gestational sac or the size of the fetus on ultrasound. The exact time of delivery varies from person to person, and the expected date of delivery is only used as an important reference information. Pregnant women should undergo regular labor checkups and maintain a good mindset and lifestyle before delivery.