The last site that disagrees for everyone else, is the only one that has it right for both of the children I already have! Going on their birth dates, both charts said boy for first, then both charts said girl for second, and now they both agree that this one will be a boy. I've always thought if we had a third it would be a boy, I'll be very surprised if we have another girl!
I think that my due date will get put back to around 20th/21st once I have my scan. Going by my lmp of 11th March it would be the 16th, but I know we didn't conceive on the 25th like the due date calculators expect. I think it will have been the 30th or 31st March. When I have my 1st midwife appointment I'll probably tell them to change it from the 16th, I'd rather go to my scan knowing it was about right than be put back by almost a week once I'd had it! My guess for when baby will be born is Dec 23rd.