Can I have too many anti malware programs?

I have been told to only ever have one antivirus, so I run norton. But i run malwarebytes daily, and spybot search and destroy. I have some sort of virus that none of these can find. It hijacks my web browser. Before I go downloading any other scanners or malware remover tools I just want to make sure I'm not doing any more harm. Is there some other way I could figure out if the virus is still on my computer, or is it possible it's already gone but the damage is done?