Dear user. FERTILE PHASE is the phase of a female's menstrual cycle when an egg (ovule) is released from the ovaries. In humans, ovulation occurs about midway through the menstrual cycle, after the follicular phase. The few days surrounding ovulation (from approximately days 10 to 18 of a 28 day cycle), constitute the most fertile phase. So if you have ejaculatory sexual inter course from day 10 from the first day of period and to day 20, the chances of pregnancy
are much more. There are many determinants of pregnancy. You should be sexually matured. Your partner should be sexually matured. The period of your partner should be in the fertile stage. Female egg and male sperm cells should be healthy enough. Then female uterus should be capable to get conceived. If all these are satisfied, the pregnancy could be a result. Take care.