Harmony Bloodwork This AM...and SO NERVOUS

I'm going to have my blood drawn for the Harmony labwork this AM.  I am also having gender tested.  I am a complete wreck and haven't slept all night.  This will be our last child and I've been praying for a girl.  I have 3 beautiful boys who I love to pieces, but I do feel the void of not having a daughter.  I fear the feeling of being heartbroken if the baby turns out to be another boy.  :( :( *tears*