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For your information, in case, a woman has a 28 day cycle regularly, ovulation is expected to occur around the 14th day. Having unprotected sex during day 12 to day 16 of her cycle, also called Fertile period increases the chances of pregnancy. Similarly Day 16 is the most fertile period in a woman with a 30-day cycle, and day 18 is the most fertile for woman with a 32 day cycle.
Intercourse before and after this time interval does not result in conception, and it is normal for some amount of semen to leak out, after intercourse.
In case you are planning to conceive, you should time your cycle accordingly and have intercourse in the fertile period of the cycle.
In addition sexual positions, that direct the semen towards the uterus [like — man on top (missionary position), doggy style, side by side] will be very effective in conceiving. You may also lie in bed for twenty minutes or so after sexual intercourse rather than jumping up right away and washing up is also advised.
I hope this helps.