The point of this post was about a luteal phase anyway,which you need certain amount of days in order for pregnancy to achieve.I myself have been in this position,after trying for 8 years,even though concieved my 17 year old no problems.after under going fertility treatment it was then we learnt that a lutheal phase is an important part of a womens cycle.Hehe ark at me going off on one.sorry :)
most woman who have a regular cycle can be assured they will no when they ovulate.ovulating later or early would normally means there cycle is irregular. a womans luteal phase is always the same.point im making is after ovulation is a safe period.until the next cycle.
The majority of women don't know when they ovulate though, and late/early ovulate can occur too in women even with regular cycles. It would be safe to just never have unprotected sex if they dont want children. No point in risking it.
There is always a safe time during a womans cycle when you cannot concieve,ie after ovulation,as said in my post if a woman has a shorter cycle ie 24 days then chances are she would ovulate just after cd10,hence having sex towards end of period could result in pregnancy,pregnancy cannot occur during a period,as the linning needs to build up.
Pregnancy can occur if a woman has sex during her period or any time in your cycle. My mother got pregnant with me when she had sex during AF. The moral of the story is unprotected sex leads to pregnancy. If you don't want to get pregnant use birth control.