Stitch like pain?

[BKR123]

So I've just arrived at my boyfriends work again but this time about 1/2 mile in I started to get a little cramp but it went away and then returne about 3minutes later a bit worse. Now it's coming and going but feels like a stitch pain, but it does go and it starts gets bad then stops. Feel like I'm being stabbed in the back too. Could it be the start?x

 

[Sam2013]

I get this when I'm walking and I'm only 28 weeks x