Q: I am giving you my past four months menstrual periods' dates. Based on these could you please tell me when will I ovulate? April 16, May 19, June 19 and July 24. What is my most fertile period this month to conceive?

A:Your cycle length is 31-35 days. This variation can result in slight difficulty in conceiving as it becomes difficult to point out when ovulation will occur. Ovulation occurs 14 days before next menses. So in a woman with 28 days cycle it occurs on day 14 (1st day of cycle is 1st day of menses). Fertile period is +/- 3 days of this day, i.e for a 28 days cycle we calculate fertile period as day 11 to 17 day of cycle. In your case ovulation will occur anytime between day 17 and day 21 of the cycle; so fertile period would be from day 17 to day 25 for you. Best is to have follicular monitoring done by ultrasound and have timed intercourse. However, you must have at least 2 postcoital tests done during the right time i.e., when follicle has reached a good diameter (generally taken as around 20mm). Also, it is good to get a serum progesterone test done 7 days after ovulation has been documented by ultrasound. A lot of important information is gathered by this monitoring and many women have conceived within 2 cycles if everything was normal. You should contact a gynaecologist.