Comments about my bump are scaring me

I am 15 weeks pregnant with my first baby and I am really showing. I didnt have morning sickness but I felt STARVING in my first trimester, I maybe gained 5-6 lbs. Around week 13 it’s like my belly just popped out. I work in an environment where I interact with a lot of people during the day and I am getting so many comments about how big my stomach looks and it’s starting to make me feel like maybe there’s something wrong with me or the baby?

“are you sure you’re not having twins?”

“Are you just eating too much?”

“This CANT be your first”

I am shorter (5’2) and small framed, and I’m in great shape, I haven’t really gained weight anywhere else. I don’t even have any symptoms, if I didn’t have the bump I would forget I was pregnant.

Should I be concerned? Or am I just talking to so many people a day I’m bound to run into a few jackasses?