full bladder for ultrasound??

ashia • married 08.09.08. first round of ivf - two embryos transferred & blessed with boy triplets!! ftm due early 2017
I have my first ultrasound tmrw and was wondering if you need a full bladder? I'm almost positive you do but I don't have time to call before my appointment! better safe than sorry, right?! the worst that could happen is i pee myself 😂😂