I know it's easy to say(!), but I wouldn't be too concerned ATM. Even at 19 weeks my belly definitely changes from day to day. Some days it's bigger than others. I know I had a little bump at 8 weeks too, but don't forget that your baby is only very tiny at this point, so it's more likely to be bloating and fluid causing the bump, as Sherie said. I know I was quite bloated.

As long as you don't have any cramping or bleeding, try not to worry, and make the most of having a flat tummy while you can LOL!