Well googling is the worst thing you can do, I know from experience. During my pregnancy I measured small once & a week big another time. Those measurements are not exactly accurate. I think a lot has to do with the babies position in the womb. As long as she stays healthy the baby will be healthy. Best wishes!
Samantha, SAHM to Caden (12-24-10), Wife to DH, and blogger at Stir the Wonder