Bengal - my ob always measured me too. I only ever measured about 4 weeks ahead of my dates. All up I only gained about 13 kg's - although some of those kilo's replaced the ones I lost from morning sickness. I had progressive shots on FB too (let me know if you want to see them ) and lots of peope commented "Are you sure there is twins in there??" to start off with which I hated. My girls were quite small when they were born at 35 wks but they are beautiful, thriving girls.

Good luck - twin pregnancies are amazing x