Zopiclone overdose............?

Does anyone know what the LD50 of zopiclone is? I have been prescribed Zopiclone for about a month now (7.5mg) and stupidly enough managed to just took 3 thinking they were propranolol. I know for a fact this is not the lethal dose and I'm sure i'll just hallucinate a bit and go to sleep (really bad for hallucinations, but somehow enjoyable ha). Also i have been on Diazepam and Lorazepam in the past 4 months, do these drugs have a cross tolerance? cheers.