I'm 18 years old and my girlfriend is 16 and pregnant with my child, can I go to jail for that?

In most states, the age differential for sex between minors is 2 years.  In some states the law was changed to 3 years. For instance, in your case, there was a 2 year age difference between you and your girlfriend at the time that you had sex.  therefore, you are within the age difference where the state does not consider the sex to be illegal even though it was consensual.  Nevertheless, i suggest that you contact a lawyer in NY to confirm that this is the case in your state.  I know that this is the rule in CT, and that NY is very similar.  Your girlfriend's parents will be upset, but they should be supportive here and want the two of you to work out for the sake of the child.  you being in jail in not a solution or likely.

The age of consent in New York is 17 and thus you can be subject to being arrested for statutory rape since you were an adult and she is a minor. The prior answer incorrectly deems you a minor which is not the case. Even when you are 17 and she was 15 you were in danger of committing statutory rape. This can be serious and I suggest you consult an attorney to prepare you in case your suspicions are correct. Since she is considered a minor she cannot legally consent to having sex so even if she did not want to have anything happen to you and said she was a willing participant you are still criminally liable. Normally in this situation the district attorneys office will not pursue without her coming forward but since you have a child you have no defense and if the parents pursue it, you may have problems. If you really are concerned you may want to try and reach out to them to convince them that you will do right by their daughter and want to be an active presence in their grandchild's life. However, please do yourself a favor and consult an attorney now.