I heard a girl can only get pregnant on the 14th day of her cycle, is this true?
No, that’s not true. A woman has a good chance of becoming pregnant from unprotected vaginal intercourse during the six days of her cycle that end in ovulation (the release of an egg). Ovulation usually occurs about 14 days before the start of a woman’s period — the beginning of her menstrual cycle. She is less likely to become pregnant from unprotected intercourse in the day or two following ovulation, but it’s still possible.
Since ovulation occurs 14 days before the start of a woman’s period — not after the start of her period — it can be difficult to predict. (Day one of the menstrual cycle is the first day of bleeding.) Also, many women have menstrual cycles that are not the same length each month.