"Safe days" usually means "when can I have sex and not get pregnant." But you titled your post "infertility," does that mean infertility is a problem for you and you are trying to get pregnant?
If you are trying to GET pregnant, your most likely days are from the end of your period to the midpoint of your cycle. If you're trying to avoid pregnancy, avoid more days than that, since you really can't be sure you won't ovulate at an irregular time.
What do u mean by safe days? We are ttc and I had pretty much a week before expected ovulation could happen. Though I have been charting. 7 days safe of no ovulation and six days of expected ovulation.