18 wks 4 days....tiny bump

lewispm

I am 18 weeks and 4 days today and, after looking at all the bump pictures on this site, I have become nervous. My bump is very small, barely noticeable to most of my friends, but I can tell its there. Why is it taking so long to form a bump? I am having a gender reveal party this weekend and most people cant even tell I'm pregnant yet. I know people show at different times, but what causes someone to show so late?? Thanks!

Here is a pic from 18 weeks, i feel even smaller now than when I took the pic!:

http://www.thebump.com/profiles/lewispm/media/photo/edit/1381901#nav