I thought I'd do this as a comparaison... I have been taking pictures weekly since Week 15. There hasn't been a weight gain from one pic to the other, but my theory is that my weight is just 'redistributing'.

The one on the left is at 16 weeks, the one on the right is 19 weeks (yesterday).

Here's 2 fun videos that I found on youtube.com:

http://www.youtube.com/watch?v=pMpMoeIgwoQ&mode=related&search=

You can see the baby moving around inside. Mom is lying on her side.

http://www.youtube.com/watch?v=aU6ojtBW0Qo&NR

9 months of gestation in 20 seconds. It's really neat-o, and I wish I thought of that idea first!

Enjoy your week!