The discharge is just a clue to when the window of opportunity is. There are at most three days in a woman's cycle when an eg is viable. Your best bet is probably to get one of those ovulation test kits that checks your urine for the hormone present during ovulation. When the hormone is detected in the first urine of the morning, you have 24 to 36 hours to be sure intercourse takes place.
About half way through your cycle. The mucus is an indicator of when you will most likely ovulate. You are looking for mucus that resembles egg whites. It happen just before and is ideal to help sperm move along. there's actually only 72 hours in which the egg is ideal for conception once released. If you are having discharge have sex every other day for a week or so. I don't like estimating chances either you will or you won't. There are no guarantees.