Firstly, no that is not too much, many 16 year olds jog that and more a day, and it does no harm to them. Too much reading methinks
Secondly, (relating to the breathing pattern) I find that once you start jogging you get set into your own breathing pattern; basically whatever's right for you. You should try and keep your breathing as deep as you can for aslong as possible, as once you get into shallower breathing you start to get more tired. That's what I think anyway, and I'm generally not bad at long distance running.
Hope that helps.