Can't feel my uterus .

Natalie • 1 miscarriage , & now pregnant again with my rainbow baby 12-21-2015 ♥
So I am 13wks 5 days and I can't feel my uterus , everyone says you should be able to feel it around week 12, I haven't got an ultrasound since week 7, idk if my baby isn't growing right or if I just can't find / feel it .