I didn't fall for a few weeks after I got my clipless pedals.

Now I think I've gone down four times... All but one were very slow speed brain fart types of tip-overs. The other one, well...it wasn't due to the pedals! Keep your eyes on the pavement and keep away from those bike eating cracks!

Falling is ok. It's not fun, but you do learn what to do when you realize you're going down.