Ohhh, I like this question! As you said, there are pros and cons of working outside the home or working inside the home (and don't let anyone tell you stay at home mothers are not working!!)
I was fortunate to be able to be at home when my kids were young, although at times it would have been nice to have more people to chat with who were more than 3 feet tall....

It helps to get involved with neighbors, mother/toddler groups, friends and family so you feel connected to the outside world still. When I did go back to work, I did so teaching preschool again, and my younger kids were able to be there with me. Once they were older, I went back to finish my degree and started teaching elementary school. I love it!! It is a great profession when you have children. You are out of school when they are, you can have them at your school, the income won't get your rich...but if you are sensible it works (although I know quite a few teachers who do work second jobs to make ends meet). Yes, there are less stressful jobs, and jobs that pay a good deal more, but there is no other job that lets you have the family time while making a decent living. Obviously it helps tremendously if you love working with kids.
If I had to do it over again, and was in your position....I would finish my degree first. Teaching works well with taking time off for children....you can take a year's leave if you want (not paid of course) and go back to your old position. Some teachers also do job shares where one teacher teaches the mornings and another the afternoons with the same class so that they have more time with their own children.
Good luck with your decision.....if you like children, I say go for it!