I didn't find out with mine, and didn't with my surrogate babies either--including twins. But, I think I might this time. 11.5 years difference and this being quite a shock has me well enough surprised to last until delivery!
I think that not finding out the sex is one of the few true 'surprises' left out in the world and I'd not change not finding out. My sister is pregnant and due just after me, as she has already 'claimed' girl (she thinks...LOL...they aren't finding out) thus by her thinking I get boy. LOL Fine with me. I have two and another is great :) but girls sure are fun to sew for!!!
For GN baby clothing, check out www.hyenacart.com It's work at home moms, and lots make custom outfits so you could get your bright and get whatever you wish :)