MacBook Pro :: How To Get Rid Of A Virus

I know most people say Macs don't get viruses..but earlier I received a notification on twitter that I had a new follower.I clicked on the persons name and it brought me to a new page. It wasn't her twitter profile, but one of those scam-looking- type pages. I didn't even read it, I just ex-ed it out.   

In the past, sometimes things pop up, I ex out, and thats the end of it. Every time I try to open a new tab, new window or click into something (like pressing "submit", or "next", or a name on Facebook), one or two other tabs open, obviously those fake/annoying pop up sites, come up.

On my preference settings on safari, it is NOT clicked to go to the new window/tab when opened, and I have "block pop-up windows" selected. (All of the options are selected on the security tab) 

I haven't recently changed any settings and this extreme amount of pop ups with every click just started happening after the twitter page thing. Should I avoid putting any personal information into my computer (Ex: checking bank account) until the pop ups stop?I don't think its happening when I try using chrome… Could it just be a safari thing? 

Info:
MacBook Pro, OS X Mountain Lion (10.8.5)