We didn't find out either time (we did consider it the second time). But ultimately, onesies, diapers, and breastmilk/formula are not gender-specific ;)
Amazingly, we had everything we needed, and were fully prepared (well, as prepared as new parents can be) without knowing the sex of the baby. And hearing my husband say, "It's a boy!" was an amazing moment.
http://blogs.babycenter.com/mom_stories/06112012-7-reasons-not-to-find-out-your-babys-gender/