Hurting calves

chetan04

So, I'm a fitbit flex user for nearly 3 weeks. I enjoyed 2-3 rest days (not exactly rest days) I walked a lot but didn't run at all. so today I went back to running on a treadmill. after just 5-6 minutes of jogging, my calves started to hurt like anything. I couldn't go further.. I usually jog for 35 minutes on treadmill and I get 12K steps on average.. But today with just 1000 steps in 6 minutes of jogging, I couldn't go further! Why is it happening, is it because of the rest days? am I doing something wrong?