I'm only 18 weeks gone, but have been having a rather strange, unconfortable sensation every so often for the last couple of weeks - it starts towards the top of where my bump would be, sweeps down in tight but random pulsing waves. The feeling is a very 'shallow' feeling ie not like a cramp or round ligament pain or anything else - it definitely feels on the outside of the bump!
It's taken me by surprise a couple of times now, and is usually so uncomfortable it's borderline painful, but I can still walk and talk (just, often puffing a little like I've been winded) then after 30 seconds or so it goes.
I have no other weird symptoms, apart from the resettling feeling after a wee on occasion as uterus moves back down, no bleeding or cramping or anything like that.
Could this be Braxton Hicks? If so, isn't 18 weeks a bit on the early side?