Is the girl fertile before her period?

Answer 1

Unlikely.

A woman will ovulate around 14 days before menstruation, and she is fertile up to 7 days before ovulation when there is fertile quality cervical mucus present. At most even if multiple eggs are realeased during ovulation there is still only a viable egg present for up to 48 hours after the start of ovulation - thus by the time a woman is due to menstruate any eggs released during ovulation are long dead.

There are exceptions - for example a woman may have a very short luteal phase (phase between ovulation and menstruation) so she may ovulate less than 14 days before her period. Women can also bleed thinking it's menstruation when actually it's not.

The only way to tell for certain when a woman is fertile or not is if she uses fertility awareness method to monitor her cycles on a daily basis.