I'm not a teacher, but here's my opinion
Before you make a decision you should try to get into a school, whether it's through volunteering or subbing.
While doing my undergrad I was in a volunteer programme that allowed me to go into a couple schools and work with the teachers. I got to see the environment and do a bit of work, but didn't really get to teach. I thought it was ok tho, so i eventually went into "teacher's college" (B.ed)
Last year I was going for my B.Ed...it's just a one year post-grad degree. Well after my first practicum I dropped out, for reasons stated below. Everyone urged me to go into teaching so I tried it out and discovered it wasn't for me....I also realized there were A LOT of other education students there who were doing it just "in the meantime". they really didn't want to teach....of course those students didn't last long either...
This year I'm a part-time language instructor in a high school.(no certification required for this) I see nine ESL classes once a week. This gave me an opportunity to teach and to try out different lessons without dealing with exams, tests, or marking.
This job only verified that I made the right decision in dropping! I am horrible at discipline and classroom management...the whole thing is just soooo stressful!
Fortunately, I have a new direction...I'll be returning to school for my MLIS next year!
So basically I'm just saying you may not know if you'll really like teaching or not until you try it, thus it may be better to find a way to at least get into a school and check it out before you spend $$$ on more schooling.....but even with in-school experience, you could end up like your friends who decided it wasn't for them after 2 years or so...