Yes. if you are 18 you can be prosecuted.
Yes, he can and he will be held responsible for the child.
you bet The 18 year old could be charged with unlawful sex with a minor child, rape, and could have to register as a sex offender everywhere he goes to live for the rest of his life.
No...
You could be pregnant - take a test
Very unlikely.
Yes.
Getting pregnant requires sexual union (or artificial insemination). If you have had either you can get pregnant.
There could be a variety of reasons. It could be that he wants you to get pregnant, or it could be he is scared to death of you getting pregnant. He could just have an odd sense of humor. The best thing to do is to ask him. If you are in the type of relationship that this is a topic, you need to start developing some open lines of communication directly with him.
they probably could if they wanted..
Unless you are seriously overweight, don't bother with getting thin, it could be bad for you. Concentrate insted on getting healthy - eat well and get exercise.
There's a 25-75 chance favoring that you would not get her pregnant. You could use a condom and not get her pregnant, or you don't use a condom and you have a chance at getting her pregnant.
There could be charges against the adult. The boy shouldn't be an issue.