So I'm just a little worried. Had my 34 week checkup and I'm measuring about 31 1/2- 32 cm for my fundal height. My OB is sending me for an ultrasound next week to make sure LO is growing appropriately. I just hope everything will be ok.

I'm sure she is. Just keeping positive.
Re: Fundal height measuring small!
09/23/11 - Married DH
04/01/13 - BFP at 4wks
05/30/13 - MMC - BO @ 12wks 5d
08/29/13 - BFP @ 4wks 4d
09/17/13 - 7wks 2d - Normal HB Detected! Baby measuring perfect for dates and positioning!
10/23/13 - 12wks 3d - Perfect NT scan! HB 167 & baby wriggling, waving & yawning!
12/17/13 - 20wks 2 d - We're having a beautiful baby girl! Go Team Pink!
05/03/14 - Bobbie Gloria was born at 39+6 weighing 6lb 14oz!
I really hope your ultrasound goes well, and no intervention is needed.
PPs also make good points that the way you are carrying can make a difference. Also, if you've been having the measurements done by a different person each time (I do. Teaching hospital = always a new resident), that can change things. Everyone does it a little differently.