Sex in the ovulation period, not necessarily pregnant, although in the ovulation period, pregnancy will be affected by many factors, such as sperm survival time, egg survival time, sperm speed. 1. Sperm survival time: after intercourse, sperm survival time in the vagina, on average, 3 hours, cervical sperm can survive for 5 days, tubal sperm can survive up to 10 days, usually considered within 48 hours of the ability to fertilize, within this range of sperm and egg combination, it is possible to get pregnant. 2. Egg survival time: women only row 1-2 eggs per month, the egg into the fallopian tube can survive about 18-30 hours, more than the time range, can not form a fertilized egg. 3. Sperm speed: fast sperm need 10 minutes to pass through the cervix, uterus, to reach the fallopian tube, ordinary speed can take between 1 hour to several hours, for oligospermia, weak sperm, it takes longer, within a certain time to reach the fallopian tube, it is possible to conceive. In addition to this, it is also affected by the patency of the fallopian tubes, so you may not necessarily get pregnant after ovulation, but you need to seek medical attention for symptoms of menopause and closely monitor your HCG levels.