Cramps

So I’m almost 30 weeks and I haven’t done much exercise this pregnancy but I’ve been walking lots. Today I went for a walk, nothing different about the walk, same pace as usual, and I got the worst side cramp of life!! As I’ve said I’ve been regularly walking this whole time and this is the first time it happened. Baby is kicking and all - I’m at home resting, but I’m just wondering if anyone has experienced this? I’d understand getting cramps if I hardly ever walked, or walked faster than normal, but I literally changed nothing from my routine 🤷🏻‍♀️ the cramp lasted about 10 minutes. I wanted to stop walking but I had no where to sit and I was pushing my toddler in the stroller and she screamed every time I stopped lol so I just slowly walked through the pain. But man it was intense!!