we just had another one at 12:39am Monday 4/21
It is listed as a 4.5 (my guess is will be downgraded as it did not feel as strong as the 4.6 we had at 10:14am 4/18)
http://earthquake.usgs.gov/eqcenter/recenteqsus/Maps/US2/37.39.-89.-87_eqs.php
It wasn’t nearly as long as the Friday morning aftershock, either. That might be why it didn’t feel as strong.