it doesnt matter what position you are in If you Have unprotected sex you can get pregant. and even protected sex is not a certainty because condoms can break. take the morning after pill if you are worried *you have 72 hours to take the morning after pill for it to have any effect.*
yes you can get pregnant sitting up. anytime of the day,week,month you have intercorse in any type of position you can get pregnant. you can get pregnant if he "pulls out" beofre he ejacualte. anytime he enters you you have a chance at getting pregnant