When you're on your period, your hormone levels are low, but that doesn't mean your libido is zero. While some women avoid sex during menstruation, others are ready for action.
The decrease in the level of hormones, which occurs at the beginning of menstruation, leads to the absence of premenstrual complaints, so some women feel calm and balanced, so they are in the mood for sex.
One more reason for strengthening the desire for sex is your humidity. However, during days 6-11 you probably won't feel hot for sex, because your hormones are geared towards thickening the tissue that lines the uterus (the body prepares to get pregnant).
Passion tip: If you want to have sex but lack sexual energy, tease yourself by daydreaming. Take a few minutes to fantasize in bed before you sleep, or during your morning shower, fantasize about making love to your partner. /Telegraph/