I agree with Loli.. since I've been focusing on exercise the last couple months, a lot of articles I read on getting cardio mention, making sure you break a sweat (which I'm sure you're doing with your jog) and just getting your heart rate up (again.. I think you're achieving that).
Also, when you start jogging you really should only add more distance or time gradually so that your body has enough time to catch up.
You're doing awesome! Keep up the awesome work!!