Its a few Qs actually, these questions are actually quite embarrassing.
1) Does everyone know like while sex is happening position comes next, or is it something that's talked about? Do you just know?
2) Why do people like Anus sex? Its going up the Hine-ee.
3) Doesn't it smell? How to get rid of smell?
4) Can a girl become pregnant from masturbating?
Nothing to be embarrassed about I promise! Here are some answers:
1) When it comes to changing positions, most of the time nobody knows what position comes next. If you change position during sex (and lots and lots of people never do) you usually do it because one or the other partner thinks a different position would feel nicer, or maybe the position they're in is tiring or less comfortable. Sometimes it's out of curiosity. And often it's just for fun! Oh yeah, and sometimes it's because the next position just feels right for both of you.
Mostly just remember that sex isn't really something to measure or keep score with. There's no "correct" number of positions, nor is there a "correct" order either.
2) Anal sex: first of all, not everybody likes anal sex. And not everyone has the same reasons for liking it, or disliking it. As Heather mentions here it's not everybody's cup of tea because a lot of people don't have the "big-time patience or level of communication skills with their partners that is really required to make it anything less than pretty uncomfortable." I'd like to add to that that a lot of people seem to think of the anus as "one more hole" that fingers or body parts could be inserted into, and that anything that could be done therefore should be done. And finally, sometimes for people who just get off on pushing boundaries want to, well, push boundaries. Although I think there are perfectly valid reasons to at least experiment with anal sex, none of those three qualify as good reasons.
3) Smell and hygiene: Yeah, anal sex play can smell whether or not insertion takes place. There's a great article all about it right here at Scarleteen. As for cleanup, washing with ordinary soap and water probably works best.
4) A girl can't get pregnant by masturbating, at least not all by herself.