Pay sales tax with the Retail Sales Tax Return For Occasional Sales (DR 0100A) on the tangible personal property included in the purchase of the business by the 20th day of the month following the sale.
So, to avoid pregnancy she has to better avoid unprotected sexual intercourse in this period. The rest of the days i.e., starting from menstruation to the 10th day and again from 21st day up to menstruation are the safe days or the safe period to avoid pregnancy.
Safe Period Calculator : Hypothesis. The menstrual cycle, is commonly divided into three phases: the follicular phase (pre-ovulatory phase), ovulation, and the luteal phase (post-ovulatory phase). The length of each phase varies from woman to woman and cycle to cycle, though the average menstrual cycle is 28 days.