Dating a third year med student
It'd be nice to have a wife through medical school and residency, but only if your relationship is healthy, and you guys are united and have lots of real love Just get married whenever you want to. It's great to have a partner to support you, someone to look forward to coming home to at the end of the day - a reason to get your work done and go home! School doesn't get easier after M1 until M4 year.
Learn to be a person that also happens to be going to medical school, rather than letting it define your life. I'm not married and I'm not in med school, yet. But then this is followed with residency, including the tough intern year.
It might sound harsh, but ignoring the fact that you change as a person by the end of your four years is naive (and, if I'm being honest, a bit irresponsible, as she will be legally tied to your student debt when you get married).
Look, if you are going to spend the rest of your life with this person, then waiting a few more years to get married won't matter in the long run.
OP is saying that he/she is a sophomore in undergrad right now and in a serious relationship so they may have already possibly gone through stuff that would test their ability to "make it last" through med school despite the big changes.
If you have a strong relationship, where you guys are united and work together, and don't argue or cold-shoulder each other, but can consult on things and work together as a team, then talk about it together!
For medical school, and residency, you'll have someone to come home to after your shifts, and someone to help cook for you and take care of you when you need.
Chances are you will grow together with your SO, but maybe you will find that you don't - I know of a significant number of relationships that don't make it through the strain.So far the most difficult thing has been just adjusting to the lifestyle.