Me and my boy friend had anal sex on the second day of my period, and he ejaculated inside my anus, so is there any possibility of getting pregnant?

Anal sex in period: Very, very low probability, basically nil, if you have a normal > 20 day cycle( you ovulate 14 days before your period so in very short cycles you can ). But if it was not during your period the probability could be higher because of leakage and movement, so it you did not wish to get pregnant use birth control

No: There is no internal connection between the anus & the vagina so anal sex does not lead to pregnancy. If any of the fluids from the excited male penis make their way into the vagina during other parts of the sexual encounter, a pregnancy may be possible.