I say go for it. It sounds like you have thought it through pretty carefully, and you don't have anything to lose - you can always come home again if you find it's not for you, but you won't know if you don't try.
It's very hard being a mum in these "enlightened" times, when the world seems to make us feel guilty no matter what we do - if we stay home with the kids, work part-time, or have a fulltime career. the best thing you can do for your kids is be a positive role-model, and show them how to go after goals and achieve them - a happy, fulfilled Mum is the best mum. It sounds like you really love your kids and would make the most of the time you get to spend with them on the weekends, and those 19 weeks will probably go really fast, you'll be learning so much! Plus your older kids will get to skite to their friends about their cool Mum being a cop!
You have to do what you feel is right, don't let anyone make you feel bad about whatever decision you make. Good luck, let us know what you decide! smile
This new forum is strange ...