No, that is not possible. And i'm sure the "period while pregnant" is just your regular period. Good luck!
It actually is possible, however the odds are very remote. The distance from the anus to vagina are small, and sperm can drip down and into the vagina. Again, this is extremely rare, but it's not impossible.
As for your period while pregnant--no this doesn't happen.
you can not get pregnant from anal sex, because babies don't grow in your stomach or intestines. They need to grow in your uterus... that is connected to your vagina.
there are cases of pregnant women having their regular period while pregnant. but i dont think it is possible to get pregnant by anal sex.
simple answer no it isn't possible. if it's a normal period for you then no you aren't pregnant either.