Bleeding after a wreck. 🩸🤰🏾

I went in to the ER last night because I was having some bleeding after a minor wreck. Baby is fine. Heart rate is 157 and it was moving around like crazy. Turns out I have a uti and a subchorionic hemorrhage. The only thing that concerns me is they have me measuring 2 weeks smaller than I should be. My last measurement at my ob was 9w5 days and they are saying the same here but I should be 11. Anyone know if they differ with measuring at the ER vs in OB office? They said they aren’t that concerned and the baby looked MUCH bigger to me so I don’t want to stress either. Just wondering.