A. It depends how long after actual ovulation. If one knows the actual date of ovulation, conception can occur up to 72 hours after ovulation as sperm can live inside the cervix for up to 72 hours under ideal conditions. An oocyte/egg has at least a 48 hour lifespan after ovulation. As you may know the most likely time to conceive is about 14 days before the start of your next period. So if one had a regular 28 day cycle, ovulation is around day 14; a regular 34 day cycle will have an ovulation around day 20. If one has a regular 24 day cycle, ovulation can be as early as cycle day 10.