Abdominal Cramps When Walking

So, recently at my job we moved to a new location. We used to have a parking lot next to the building, and now where we moved, we park in a garage and walk two blocks. Now, I go for occasional walks anyway, but normally more leisurely, slow walks... Going back and forth between the parking garage and my office, I usually walk a little faster.. Being pregnant and working in the city, I don't like walking alone that far... With all that being said, I have noticed if I walk a little quicker, OR for longer periods of time, I start to get cramping in my lower right abdominal area. Is doesn't feel like round ligament pain, it feels more like a cramp you would get in your calf from now stretching well and running.... Is anyone else experiencing cramping like this? I'm 24 weeks today....