If I'm 18 and get my 15 year old girlfriend pregnant, will i go to jail?

In Texas if the child is under the age of 14 it does not matter if the sex is consensual. It is aggravated sexual assault of a child and if that sounds bad it is. 5 to 99 to life in prison. If the child is between 14 an 17 there is an affirmative defense that there is less than 3 years difference in age. If you are 3 years 1 day older and the child is under 17 it is a 2nd degree felony sexual assault of a child 2-20 in prison. Since you have been with her for 2 years I presume you may have had sex when she was 13. Not good. My advice is that you break it up now. No more sex until she turns 17 and even then that is not good. You all do not need a child at your ages. Hope for the best and that the law does not come down on you

If you have sex with her (or sexual contact) regardless of whether she gets prosecuted, you can go to prison if you are one day more than 3 years older than her. She does not have the legal right to consent until she is 17.

Other lawyers have provided good responses to your questions, so I will try not to repeat the things that they have said. A link to the statute that would most likely apply to your situation is available here: http://www.statutes.legis.state.tx.us/Docs/PE/htm/PE.22.htm. Scroll down to "Sec. 22.011. SEXUAL ASSAULT." The statute is a little wordy. However, if you read it then you will learn what constitutes sexual assault and what is considered an "affirmative defense" that will keep you out of trouble. Once you read the statute, you should hire a lawyer if you did not know what it means and how it applies to your situation. Finding a lawyer to decipher the statute during the course of a 1-2 hour consultation is likely to cost from $150-$500. One of my offices is located in Austin, so I am happy to help you. However, most Texas lawyers can easily assist you with this matter.

You could potentially be charged with multiple counts of sexual assault and could be looking at significant jail time and you need to make an appointment with an attorney to discuss the whole situation.

This depends on the age of consent in your state. To be safe, you should consult with a defense attorney in your area ASAP.