Completely normal. I remember running into a bench one day at acupuncture and nearly knocking it over. I was so apologetic, but the woman I saw was also pregnant and explained that the clumsiness was completely normal due to raised progesterone levels. I guess it just becomes more obvious towards the end as you are so much bigger, too. And when you think about it, your centre of gravity has also changed fairly significantly in a relatively short period of time.

BW