I am 31 weeks as well! I think you look great, you have a cute round belly! My stomach is slightly smaller looking I think it's cause my belly isn't as round as yours. Plus I am 5'10" and I swear she's hiding out in my back haha.
He finally dropped out of my rib cage (he was hiding away and didn't want to come out lol) so within like 2 weeks my belly somehow went wahhhh bam . But I am just glad I at least look on average makes me feel pretty great! I just can't wait 9 weeks until he is here!