Let’s say, your average cycle length for periods across March to July are 30, 29, 27 and 30. Your average cycle length would be an average of these numbers, that is, 29.

Ovulation Calculator: Understanding Your Menstrual Cycle Rebecca Gillie— Parentdish UK 14/10/2014 12:20pm BST Getty ...

An app is probably an easier option but if you want to figure out your ovulation day yourself, you'll need to chart your menstrual cycle and record how long it lasts. According to Web MD: "Day 1 is ...

In a fertility cycle, the ideal size is between 18 and 22 millimeters in diameter. Once a follicle reaches this size, it means estrogen levels are rising and the uterine lining has thickened.