How do i calculate my fertile period?how do i maximise my chances of getting pregnant at 38

FERTILE ZONE: The fertile zone is typically about 5 days a month. Ovulation occurs 14 days prior to the next menses. For example if menses starts 1/1 and next starts 1/28 ovulation occurs on 1/14. ( 28 day cycle - 14 days = 14) Count day 1 as first day of bleeding. fertile zone is 2 days prior to ovulation + 2 days after= 5 days. Buy an ovulation prediction kit and test your urine to confirm those days