Soft uterus!

Anyone else on ther 3rd or more pregnancy and expected to show much sooner but still don't have that firm roundness below your belly button? 
I am 16 weeks with baby #3 and when I lay down I'm pretty sure I can feel my uterus but it's soft, like between my pubic bone and belly button there is a roundness but it's not firm like I remember it being with my 1st and 2nd.
Is this normal??