Never! It's not worth the risk. Assume she can always get pregnant and use proper reliable Birth Control such as the Pill, the Mirena coil or sterilisation.
If you are having a period, you re not pregnant. You cannot be pregnant until after your last period.
It's normal for the length of a woman's period to vary from month to month. Anthing between about 26 days to 35 days between the first day of one period and the first day of the next period is normal. It is not reasonable to expect your period to come on the same day every month. You know if you are pregnant if your period is a week late and your pregnancy test is positive.
No you are not
Anywhere between 1 month and 2 months pregnant. Take a pregnancy test
If you get your period you aren't pregnant.
no
Probably not.
When you are on your period
no
Humans don't get pregnant when they have a period. That's only for animals. Human females mostly get pregnant mid-way between their periods.
When you get your period it is uterus blood. Your period is the uterus shedding its lining if you do not get pregnant. All month your uterus builds up its lining for if your egg gets fertilized, and when/if it does not get fertilized, you have your period at the end of the month.
There is always a chance of getting pregnant anytime of the month. Just because it is the day after your period does not mean you can't get pregnant, you can get pregnant on your period as well.