Is it possible to become pregnant from ejaculation in the anus??

Not unless torn: If you have a tear or a channel (fistula), or a congenital defect connecting the rectum to the vagina, it is theoretically possible. I know of no cases but maybe others have heard of it occurring. Otherwise, no, .The anus is part of the gastrointestinal tract, and is not connected to the reproductive tract. A vaginal examination by a professional can determine if the vaginal wall is intact.

No...: Ejaculation is the anus will not result in pregnancy. For pregnancy to occur semen must enter the vagina. Regardless of whether you are having vaginal or anal intercourse, you should protect yourself from STDs by using a condom.

Yes...: Semen can move out and across your perineum and then into your vagina, so yes it is possible.

Determined sperm: it seems highly implausible that this could happen, even if some semen came in contact with the vaginal introitus. Those relatively few sperm would have to be awfully hardy and determined to swim the entire distance of the vaginal canal, through the cervical os, the uterus and fallopian tube, to a "waiting" ovum and still have enough energy to fight it's way through the barrier into said ovum. :-)

Yes: Although MUCH less likely. If any semen comes in contact with vaginal area -even in small amounts that may not be retained in the rectum = -it could lead to pregnancy.