Sorry to say Emma,, but the fundal height is really innacurate for measi\uring how big your bubba will be.
I have since about 18 weeks, been measuring at least 5cm ahead each visit. At 34 weeks, i was already 39cm!!!!!!
I also was shown at an ultrasound that bubba is in the 90th percentile on the charts at 26 weeks,,,.
I however have to have a caesar as it is my 4th one,,, but have been told that if it wernt for the fact i need a repeat one,, that i would have been let go to 40 weeks at least before they would have considered induction etc.
Fingers crossed things go smoothly for you hun,, just take each day as it comes,, and remember,, it isnt really that long to go (i know,, it seems like an eternity,, but once you get there,, it will all seem like a memory )