Community post

Just count your first day of period to 14 days ....n. start using the opk from the 12 or 13 day of your period....if you have a regular cycle your ovulation day must be around the day 13 to 16 of your period.....that's when the ovulation starts and last for 12 to 24 hours only...hope it helps

But i am irregular period, so i didnt know when is my fertility dates. I wanna get pregnant, but until now, its negative.. :(

Depending on how irregular you are I would invest in some cheap ovulation predictor tests from online and start testing twice a day. Usually once in late morning/early afternoon and in the evening sometime. That will give you the best idea of when you can expect ovulation :)

It might also help to start temping. A friend of mine has a very irregular cycle - she was never easily able to pinpoint ovulation (cycles ranged from 35 days to three or four months). The approach they took was to have sex every other day from the end of her period. That way they were pretty much guaranteed to hit a couple of fertile days! That's an awful lot of sex - but it did the trick for them.