I like to keep track of things. Really.
So, I convinced my wife to track her weight during pregnancy and figured, "Hey, I could burn down the weight as we approach pregnancy."
The chart tells a somewhat interesting story. When the actual is below predicted she is gaining weight faster than her doctors want. When it's above she is not gaining enough weight. The plunge in the actual line happened around holiday time when we were eating...a lot. The recent spike upwards coincides with a series of sleepless nights and vomiting that was probably caused by the flu originally and then continued as heartburn sets in at the beginning of the third trimester. It also seems that the heartburn+squashed stomach combination as the baby gets bigger will make it hard for her to keep on weight.
See more from her blog on http://preggerita.com/ including a live updating version of this chart.