Not excited about bump

I am very excited to be pregnant! We had been trying for 5 month and got pregnant with twins only to miscarry 9 weeks later. Two month after the mc I was pregnant again  (with one). We are very excited! I am currently 13w3d due Sept 25th. I am amazed at the miracle happening in me. However, I am not excited about getting a big belly. Is that strange? Maybe it'll be different when I get an actual baby bump and not just the gaining weight look. I feel like I just have fat on the side of my waist and right above my pants. From highschool on we are told that having a fat belly is bad and I've worked hard to keep my belly flat(ish). But now all of asuddenly I'm suppose to flip a switch and be ok with a big belly? When anybody says they see a bump I feel hurt and affended. I know that that is the last thing they were going for when saying it but that's just how I feel. Anybody else out there having the same issues??