The ovulation moment is caused by a chain of events that start with the estrogen reaching its monthly peak. This stimulates the discharge of LH (luteinizing hormone) by the pituitary gland under the influence of the GnRh (gonadotropin releasing hormone) produced by the hypothalamus. The LH is the main hormone triggering the ovulation but another pituitary hormone called FSH (follicular stimulating hormone) which is increased in the first half of the cycle also has a peak now and supports the ovulation.
The estrogen has to reach a certain level and has to be high for at least 36 hours for the LH to be released. Also, the dominant follicle, which is preparing for releasing the egg (ovulation), starts producing progesterone which is necessary in this phase for the LH surge to have full expression. If any of these requirements are not met then the ovulation doesn’t occur. Together with the estrogen the testosterone also achieves its monthly maximum levels.
The peak of LH triggers multiple changes in the follicle that lead to the release of the mature egg 18 hours later. After their pre-ovulatory peak the estrogen and the testosterone take a dive while the progesterone keeps increasing because the remains of the follicular sac transform into a structure called corpus luteum which produces mainly progesterone but also estrogen. Therefore the estrogen starts increasing again reaching another peak together with the progesterone at the end of the 3rd week.
The ups and downs of all these hormones lead to all the physical and emotional symptoms that you experience.
The testosterone peak just before your ovulation is responsible for your sex drive going up. The estrogen also contributes to the increased sex drive and makes you more open to having and enjoying sex around your ovulation taking up a notch the effect from the 2nd week of the cycle. This is because the egg only lives for 24 hours while the spermatozoid lives for 2-3 days days which means that it can wait for the egg to be released in order to fertilise it.
Your behavior is also influenced by these hormones and you tend to wear sexier clothes and to be attracted to men who have deeper voice, symmetrical facial features, who are confident, competitive and playful, which are features due to higher testosterone. The drop of testosterone and estrogen will be compensated by the steady increase in progesterone which will soon be accompanied by a rise of the estrogen until the end of the 3rd week which makes the libido go up again. After reaching a peak they will both drop which will cause your libido to dip again. Just another bump on the never ending rollercoaster of having a female reproductive system.
Estrogen has receptors everywhere in the body, including the parts of the brain that control moods and emotions. Its effects on the mood work through:
After the pre-ovulatory high the lowering level of estrogen leads to a decrease of the quantity of serotonin in the brain as well as the number of its receptors. This partly explains the low mood, irritability, anxiety, fatigue and sleep issues. It might also explain why you feel the pain more intensely. Some women have what is called mittelschmertz (from the German “middle pain”). This is described as a dull, cramping or sharp stabbing pain in one side of your abdomen at the moment when the egg is released.
Serotonin is a chemical (called neurotransmitter) that nerve cells produce and it is involved in mood, cognition, and the inhibition of pain in the brain. This means that the level of serotonin will partially determine how you feel, how you think, how you interpret, how you experience and the way you act in a certain situation as well as, possibly, how much pain you feel. Serotonin actually impacts every part of your body, from your emotions to your motor skills. It is considered a natural mood stabilizer and the chemical that helps sleeping, reduces depression and regulates anxiety. It also influences eating, digesting, it heals wounds, stimulates nausea and maintains bone health.
Serotonin makes you feel good so any decrease in estrogen or an imbalance between estrogen and progesterone that the body sees as less estrogen will bring the mood down. It can go down more ( towards depression) or less depending on how sensitive your brain is to the fluctuations of the hormones.