I happen to think along the lines of Nelle...

But I just wanted to offer you some reassurance. With my first, I measured behind through the whole pregnancy. I even had to have scans to check my placenta was doing it's job in the third tri and my fundal height always measured behind even at my last antenatal at 40weeks. Ro was born 9lb 2oz... so not as tiny as we expected and were lead to believe. Even the professionals were shocked. This time my Ob hasn't commited himself to an opinion. Everything will be fine - even if bubby is petite!