Wow, thanks everyone for your replies. I guess I was just a little worried that it would look rude in my behalf. But I think now, knowing what you Ladies have gone through, I will tell them it is for "their" benefit that they come later. We had our scan yesterday and all was well (although they did say it was measuring 1 week behind, but I know my AF date, and am pretty certain on my O date, as I always have regular cycles). So naturally they all asked if we had a clearer due date. I told them end of Feb, and that they had gotten a different date to me. I will wait a little bit (maybe after the 12 week mark somewhere) and mention it again, and let them know I what I would like, it is our Baby after all!
Thank you all for you advice, I figured those that have had Babies would be able to speak from experience, and tell me what they would have changed.