I just checked, and I have not yet posted an e-mail that I
sent to a nursing student.
To answer your question, don't forget that there is
residency training after medical school. Medical
school itself take four years, and family medicine
will take an additional two years past that. If you
are interested in specialising, specialty training
takes 4-6 years after graduating medical school. That's a long time, particularly if you stretch out your degree.
However, here's another point to think about. There is a possibility that you will find some bias in the admissions committee about the fact that you are a nurse applying to medical school. The idea is that you undertook professional training in a profession that you had no intention of entering.
This could be interpreted as you taking an educational opportunity away from someone who really wanted to work as a nurse; essentially there will be one less practicing nurse after graduation. Also, it may be interpreted as a shaky committment level to the nursing community. This may, and I stress may, not be a positive influence on your application to medical school. You might want to do some checking into this before you make your decision. It could just be a rumor that I've heard, but I would be remiss if I didn't mention it. With that said, there are pharmacists, physical therapists, and occupational therapists in my medical class. However, there are no nursing students.