Hi jimcarver

I had the exact same problem some years ago.
I just kept on running.
I ran shorter distances for a couple of weeks and never going fast.
And whenever I would feel the calves tightening up I would just stop and stretch them really well (and massage them too).
It was really painful for a time but it eventually went away. I guess that as I got more miles in and the legs got stronger and used to the daily routine.