With the way health care reform is playing out there's very little money to be had in medicine anymore. True, the more competitive the speciality you get into the higher the pay will be, but the level of income is nowhere close to what the top end was 10-15 years ago. There's also the insane amount of stress you have to deal with on your way towards getting that degree that will really test your mettle. MS1 and MS2 are the years you spend studying hardcore trying to absorb as much as possible before you take your Step 1 at the end of your second year that will basically determine what specialty you can get into. Then you have the dreaded MS3 year, where they put you through the wringer with long days at the hospital, frequent presentations, and shelf exams after every rotation. Tack on your Step 2 after your 3rd year and you're pretty much going all out until just before your 4th year. Comparatively, 4th year is supposed to be easier (I say supposed to because I'm not there yet and I can't validate it for myself), but at that point you have to deal with the residency application process (if you're looking for a competitive residency you're looking at 30+ applications) and then traveling everywhere to interview. Finally, you find yourself dealing with the stress of Match Day, hoping you match into a residency you wanted. And this is all before residency/fellowship, which if you're trying to get into a field like surgery you're easily looking at another 6 years before you start making "bank". If you take an average med school tuition of $50,000 a year, you're $200,000 in the hole and you have to start paying it back in residency, where you'll be making $40,000 trying to make ends meet.
Don't get me wrong, I LOVE what I'm doing, but I'm definitely not here for the money. If you want to pursue a career in medicine, make sure your motivations for pursuing it are strong. I've had classmates drop out cause they were there because of family pressure or they believed they'd be making a lot of money, only to be unable to cope with the stress of it all.
For me, I was an electrical engineer major in undergrad and took an anatomy course on a whim, fell in love with it, and changed my career path. I would suggest you take an anatomy course and a med. phys. course to see if a)it is a subject that interests you and b)you can handle the material. In the end, it's all going to come down to you and how you feel about it. Those courses will help you figure that out.