Thank you for advice, shipo!
Unfortunately, I've tried several times to go slower but my legs cramp up almost immediately and I have to stop. Did I mention my husband is also a new runner? After only one month he can jog a 12:30mm for 3 miles straight without stopping--and that's after 15 years without exercising at all. I'm so jealous!
What I can do to stop the cramping at slower paces?