estrogen is low. It rises during the follicular phase as your body prepares to release an egg, peaks just before ovulation, and drops going into the luteal phase (the phase between ovulation and your period.) You can read more about the phases of themenstrual cyclehere. ...
6 Douma SL, Husband C, O'Donnell ME, Barwin BN, Woodend AK. Estrogen-related mood disorders: reproductive life cycle factors. ANS Adv Nurs Sci 2005; 28: 364–375. 7 Schmidt PJ, Rubinow DR. Sex hormones and mood in the perimenopause. Ann NY Acad Sci 2009; 1179: 70–85. 8 ...
doi:10.1096/fasebj.2018.32.1_supplement.716.17Josh UhlornNathaniel A. HusbandMelissa J. Romero‐AleshireDennis P. PollowJennifer L. UhrlaubJanko Nikolich‐ZugichHeddwen L. BrooksJohn Wiley & Sons, LtdThe FASEB Journal