Why don't you want to buy a running stroller? There are tons of them cheap on Facebook and Craig's List. You can most likely get one for $50 if you look around. Yes, running with a stroller isn't ideal, but if it's a choice between jogging stroller or not running, jogging stroller is definitely the right choice. If your child is 4 to 6 months or older, this is unambiguously the right answer. I can run an hour with the stroller, no problem, usually 90 minutes before my daughter gets impatient. You can add those miles on top of any you have time for without the stroller.
If you want to keep running as a parent, your motto has to be "No excuses." So get a stroller, and get it done.