Hi leddle, I am a nursing student in my last semester and I also got my EMT cert before getting into nursing school. Actually, the only reason I got my EMT was because I wanted to become a paramedic. During the EMT program, we were required to put in some time at an ER in a local hospital. After seeing the role of nurses in the acute care setting and what they actually do (as opposed to what I thought they did based on TV shows and mainstream "knowledge"), I decided to change my career path and become an RN.
Becoming an EMT will give you, at most, a very brief primer to a few concepts you will study in nursing. In other words, it will barely scratch the surface of the knowledge you need in nursing. The opportunities that come with the certificate, however, is where I think it really shines. With an EMT cert, you can work as a tech in an ER during nursing school and learn a lot of the skills and protocols that nurses use. You won't be able to give medications, do in-depth assessments, start IVs, or do a lot of what nurses can do, but the hospital has been the best classroom for me during nursing school!
If you aren't sure if you even want to be a nurse, a CNA or EMT course will help you get some exposure. The problem is, the opportunities in nursing are so broad (OR, ER, ICU, L&D, etc.) that even these won't begin to give you an accurate picture of what a nurse can do. All this being said- if you are a smart and caring person that can handle challenges and isn't afraid to get your hands dirty, nursing may be your forte.