Fundal height is generally what week you are. I say generally because it is NOT AN EXACT SCIENCE. The position of the baby, how much amniotic fluid you have, will all affect the size of your uterus.
That said, your fundal height is in line with your weeks. 33 cm @ 34 weeks is normal and average. They take fundal height to make sure to track what is going on in there in terms of too much growth or too little. It could mean you have too much or too little amniotic fluid. Or it could indicate twins if the weeks are far advanced. But this method of measuring only means more testing (ultrasound) would need to be done.
You will have an average sized baby for your body