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Semen or pre-cum coming in contact with vagina or flowing into vagina can result into pregnancy if you are close to your fertile days, ovulation time (time of egg release from ovary). If you suspect chances of being close to your fertile days, then you should consider taking emergency contraception (within 48-72 hours of intercourse) to prevent chances of pregnancy. If you intend to remain sexually active, consider getting started on regular birth control measures.
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