I just had my 32 week appt a few days ago & am measuring 3 weeks behind as well. Babies position is usually the best bet as to why. Those measurements are just a rough estimate anyway & usually as long as it's not more then 4cms either way they just watch. They combine heart beat, position, fundal height, moms weight & blood pressure as a whole at each check up to assess u & baby. You have a great chance to see ur lil one again, I wasn't offered that, but am seen every 2 weeks by the OB for complications. I did ask about the babys expected size at birth & was told he'd be around 7 1/2lbs which is big for me as both my girls were under 7lbs & caused tearing.
Good luck & I'm sure u're lil one is perfectly happy :-)
It is probably just the baby's position that is making it measure small. Especially if the baby just recently turned. I am on the opposite end of it measuring 3 weeks ahead. They are also going to do an ultrasound for me next week to make sure baby is not too big. I am sure as long as all of your other ultrasounds went well and you got to hear baby's heartbeat that everything is just fine