The days after lmp when the chances of conception are most are from day 12th to 18th provided to cycle is very very regular. Planning pregnancy which irregular cycle is a big challenge for the couple there are certain methods which can be followed on to and the pregnancy would become easier for them to plan. So the first is taking the basal body temperature body temperature which is to be taken from day one of the cycle and it should be taken before the lady gets out of the bed and this should be charted through out the cycle. Rise in temperature at the time of a relation will give the way that okay this is a good time to conceive so the temperature rise will be some where half to 1 degree Fahrenheit. The second thing to be noticed is the vaginal discharge during the time of ovulation the discharge becomes very thin and copies and sometimes it may have egg or fishy odor then there some tests which are available to find out the ovulation one is the kit which is available in the market. It is basically the text search of LH hormones and this precedes 24 to 48 hours before the time of ovulation so this will give you clue and it can be done at home it is a urine test basically and the fourth Test is what the gynecologist can do this is called follicular study, in this how the follicle develop, what is the growth and when they are ovulating can be detected this is how a lady can find out which is the best time to conceive with irregular cycles.