I just thought I'd but in my two cents. I am due in three days with our first and we did not find out. I am 34 and DH is 41 so it may be our only too. I could have been swayed to find out but DH was so strict with not finding out. Becoming pregnant was such a lovely suprise and the whole experience has been wonderful so I'm very happy that we didn't - I can't wait to meet either my son or my daughter very soon. I feel that we are so lucky anyway that it simply doesn't matter - health is what matters the most.
I am also a highly organised person but really every nursery is beautiful whether it is gender specific or not. And forget about buying clothes - you get so so so so many things as gifts and some of our cutest gifts are jumpsuits with stars on them or one even has guitars - easily for a boy or a girl! Also - a girlfriend told me that for her not knowing really helped with that final push! LOL! Either way - your decision but nine months on - I'm glad we didn't!