Well, the stock answer that you would probably get from any adult is that having sex at 14 is a bad idea generally, but that is not the question you asked.
A number of statutory provisions are involved. NRS 200.366(3) proscribes sexual assault against a child under 16 years of age as being a felony which may be punished by up to life in prison without the possibility of parole.
NRS 200.364(3) defines "statutory sexual seduction" as pretty much any sexual act committed by a person 18 years of age or older with a person under the age of 16 years.
NRS 200.368 further defines "statutory sexual seduction" and provides for punishment as a felony (if the perpetrator is over 21) or a gross misdemeanor (if under 21). Case law from 1928 to 1961 seems to make sexual penetration by any male over the age of 16 on any female under the age of 16, statutory rape, although the more modern statutes might change this result in the precise situation you set out, at least as of today.
And all of this is over and above the "contributing to the delinquency of a minor" statutes, which may well be implicated for both you and your partner.
Bottom line is that your current relationship might well be violating the law. And it would appear to be certainly so once your partner turns 18. This situation is extremely dangerous for both of you, and you should probably consult with a trustworthy adult adviser who can get appropriate advice from counsel well versed in criminal law. In the meantime, you can directly access the criminal law on this subject at the Nevada Legislature's web site, at http://www.leg.state.nv.us/law1.cfm.