I was in the same situation back in August and again two weeks ago. My 18 week scan left no doubt this was DS3. I had thought before this that this was finally our little girl because this pregnancy was nothing like the first two (which were identical). The tech wasn't satisfied with the pictures of the spine after an hour on the table and scheduled another 3 weeks later. I kept telling myself (after crying uncontrollably for days on end) that they were wrong and prayed that the baby would be a girl. No luck, again very obvious the baby was a boy and again I left crying. Then I had a growth scan two weeks ago and mentioned that I was told the baby was a boy but I wasn't sure. And again, when the tech checked, very obviously a boy. Yes, I did set myself up for disappointment, but I just had to be sure. But by this last scan at 31 weeks, I have been more at peace with the gender and did not cry. Disappointed yes, but more at peace. I am still praying that they were wrong and when this baby is born (edd 12-31) I will get my little girl (although I know I won't). Hope is all I have.