i had to find out with all of mine, there is no way i could last the full 40 weeks not knowing!
we have enough trouble deciding on one name, let alone one for a boy and one for a girl. i did have recurrent dreams with dd tho that they told me the wrong thing at the scan, i panicked and spent the last 2 weeks running arround getting green, yellow and white clothes as in my dream we had a beautifull little boy, and nothing but girls clothes for him! i never ended up using any of them tho!