Can you pls tell me doc that for how long does a sperm remain alive in woman's body after having intercourse is it 7 days or more?

Usually 2-3 days: Usually 2-3 days, but anything could happen. The best course of action is to see a counselor and talk about post-coital contraception options right away.

Up to 5 days: Depending on conditions, sperm can live in a woman's body for up to five days. So, if you have sex within a couple days of ovulation, it is possible your partner can become pregnant.