Turns out after a trip to the emergency room, x-rays, and a call to poison control, it's fine as long as the mercury is still in ball form and doesn't break.
In a similar vein, at another time I had to take a steroid to reduce swelling that was causing my bronchitis. I read the directions, and took the pills, and then my mom questioned if I took the right amount. Directions were just ambiguous enough that I panicked thinking I might have over dosed on it or something. Mom calls poison control. Turns out I took exactly what I was supposed to take. So I guess that's a dumb thing my mom did kinda? XD