XP from July: 25 weeks but measuring 28?/UPDATE

RDK24

I could have sworn I'd be measuring small at my appt today (comparing myself to pics of other 25-weekers) but to my surprise my OB said I'm measuring big -- more like 28 weeks! She ordered a growth sonogram (said to schedule it at my convenience) to check on the baby's growth and fluid. She didn't seem concerned but I, of course, am feeling a bit worried.

I'm going on a little babymoon with MH on Sunday and I don't think I can get an appt for the scan today or tomorrow and I don't want to spend our trip worrying. Anyone else w/experience measuring ahead? From what I've read, women measure ahead/behind all the time but I'd love to hear any anecdotal evidence from you ladies to help me chill out. Thanks in advance.