Irregular Periods & Ovulation Issues: Conception Support

Question
My husband have been trying to concieve for about 5 months now but my menstration cycle is not consistant and I think I am missing my ovulation time, I have gone from 31 days to 30 days to now 36 days should I still go by 14-17 days after the day I start my period, I have been trying a conception calendar on line but that does not seem to be doing anyting, this month I went 36 days before starting again but this time my period my about 1/2 day long first I thought maybe I was just spotting and was pregnant, so I took a home test and it came out negative, just need some thought on when to try to concieve, when are most peak days?

Answer
If you normally have a 30-31 day cycle (from the first day of your period until the first day of your next period) ovulation will occur on cycle day #16-17 (fourteen days prior to the first day of your period). Therefore, you can become pregnant if you have intercourse on cycle day #15, 16, 17, 18, or 19.  If you are having trouble pinpointing the exact day of ovulation, I would suggest purchasing an ovulation predictor kit from the pharmacy and testing your urine starting on cycle day #15. Good Luck. Sometimes you can get a cycle that is longer than normal, but I would go by your normal 30-31 day cycles)