Fourteen days before your next period is when the fallopian tubes release an egg to rendezvous with some sperm that could start the creation of an embryo. It’s usually a one-day occurrence therefore its preferable to start having sex with the partner before the 14th day if wishing to conceive. There are many menstruation apps that aid for pregnancy planning. In addition, other methods of tracking g 0vulation includes monitoring cervical mucus and basal body temperature. The amount of discharge experienced increases just before ovulation and becomes thin and slippery. Basal body temperature can also be used such that when at rest, temperature rises slightly during ovulation (less than half a degree to 1 degree Fahrenheit) The most accurate predictor is for a blood test to determine overall fertility. This will provide insight into how many eggs there are by measuring the level of anti-Mullerian hormone in the blood and measure other relevant hormone levels that can indicate if conditions like polycystic ovarian syndrome or thyroid disorders that could impact the ability to get pregnant while trying to conceive are present.
Ref:
https://www.today.com/health/what-egg-freezing-cryopreservation-t124109 
