Unfortunately dilation and effacement doesn't necessarily mean anything... You could go weeks while 3cm. If you start noticing bloody show or consistent contractions or leaking waters call your Dr or head to the hospital just to be safe. Just try to take it easy though.

I've noticed that the days where i do more physical activities (and the day after too) i have stronger BHs and i can hardly walk due to hip, back, and cervical pain. So i try not to put too much stress on my body. Easier said than done though ?