when i was nearly due i was still fitting into my own jeans, i did not show much. be glad you have a small bump and not riddled with stretch marks :) usually bumps are bigger as you have more children, most first pregnancies are small but will still have healthy children. My wee girl was 7lbs 0oz when born so i new i shouldnt worry xox
My SIL is almost 4 months preggo with her second and she is harldy showing at all too. She just looks a little chunky right now. I think it's fairly normal. You probably won't get a nice round baby belly until 5 or 6 months. Hang in there. I too want to see my big belly soon!
And some women never really show at all, especially if overweight. I'm sure everything is ok. Hang in there and start wearing maternity clothes anyways - it might help you "show" a little more. :)
I think that since you have never actutally carried to full term that, That has something to do with it. Since your not all stretched out from mulitple pregnancies. Each pregnancy is different I wouldnt be worried.