The follicular phase is the phase of the estrous cycle during which follicles in the ovaries mature. It ends with ovulation. It begins one the first day of your period and lasts for about two weeks. At this time, estrogen (estradiol) levels are high.
Studies have shown that women are more susceptible to pain during the first half of the follicular phase. To avoid exacerbating pain, it is recommended that you postpone dermal visits, hair removal, skin peeling and other painful procedures for 5-7 days after menstruation. Pain tolerance reaches its maximum toward the middle of the cycle, and you will be able to resume your normal regimes.
However, if you wish to go on a diet or start fasting/detoxifying your body, this is the best time to do so. Estrogen is an appetite suppressant so it is more likely that you will go through with your diet if you get on it the first day of your period.