Sometimes the ovary releases more than one egg, or both ovaries release an egg during the same menstrual cycle. This is called hyperovulation (multiple ovulation). This is a phenomenon that can lead to fraternal twins if sperm fertilize both eggs in the ovulation window (12-36 hours after release).

Multiple ovulation always takes place within a short period of time - both eggs are released within 24 hours on the day of ovulation. Subsequently, levels of progesterone (a hormone) increase, which prevents re-ovulation and prepares the body for a potential pregnancy. Therefore, regardless of whether it is regular ovulation or multiple ovulation, the fertile days are determined in the same way.

There are no specific symptoms that would indicate that hyperovulation has occurred. The temperature increase that occurs after ovulation is the same whether one or more eggs are released.

The frequency of hyperovulation depends on the individual characteristics of the woman. There are a few things that can increase the likelihood of multiple ovulation, such as recent use of hormonal contraception, having fraternal twins on the mother's side, medical conditions such as PCOS, or fertility treatments.

I have attached materials that may be of interest to you:

https://www.gdziepolek.pl/kategorie/leki-na-zaburzenia-miesiaczkowania

https://www.gdziepolek.pl/blog/historia-antykoncepcji-metody-zapobiegania-ciazy-kiedys-i-dzis