Sam if you really are desperate to know post your pics on in-gender.com and there are trained sonographers that go on there and guess based on nub theory - the research has been done and given the right eye it is said to be very accurate between 11-14w. I posted mine on there after my perinatologist told me it might be a boy at 11+4w and all 13 guesses came back girl on in-gender - and I have to say when I looked at the nub I too was thinking girly - anyway my little girl was confirmed at 18+3 last week!
Let us know how you get on!