Ovulation is the time in a woman’s menstrual cycle when an egg is released from the ovary. It occurs due to a change in the level of hormones produced in the first half of the cycle, which cause a follicle in the ovary to ripen. At a certain point, the hormone levels cause a surge of a hormone called LSH, which stimulates the release of the egg, or ova, from the ovary.
At this time, women may notice a rise in their baseline temperature of 0.3-0.6°C, which may persist until their period starts. Other changes at ovulation include an increase in vaginal discharge, with a clear mucus which can be stretched in to a thread between thumb and fore-finger, and breast tenderness. It is also possible to have some slight spotting. Some women also experience ‘mittelschmerz’ or ‘middle pain’ at ovulation, which is felt low down in the abdomen, near to the groin. This due to the tough capsule of the ovary being stretched by the ripening egg.