Mild cramps/25 weeks

Anyone else have very mild cramps toward their back area here and there?  I went on a long walk with my son and didn't have much water this morning, so I'm wondering if it's maybe dehydration and overdoing it a bit.  Going to call the doc if it's persists or gets worse but just wanted to see if y'all had similar experiences.  Very mild, no tightening of the belly, no bleeding, just some crampy tinged near my back.  Guess it could be gas!