Heyoh girls

For the last few weeks - but especially just this last one - the outside of my belly's been numb. It's hard to describe accurately (I've tried to explain to DH but I think just confused the poor man ) but it's like there's an extra layer on my skin. Like I'm wearing bathers or something. I can pinch and pull at the skin and I'll only just be able to feel it, even if I'm really digging my nails in (I accidently drew blood the other day, i didn't realise how hard I ws pinching!).

The feeling (or lack thereof) spreads from about 5cm above and below my belly button, and almost all the way to my waist side to side. If Smudge is kicking, I can feel that from the inside, so it seems that it's just the outer layers of my skin/fat/whatever...

Is that normal? Is it something I should be worried about?

ETA: Just googled it, which I should've done to begin with, and apparently it's fairly common - I can't find a reason for it though, so if someone could tell me, that'd be nice