Q: How to get rid of a virus (mostly likely from twitter)?

I know most people say Macs don't get viruses.. (and I was one of those people until today!) but earlier I received a notification on twitter that I had a new follower. Curiously, 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. NOW… 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. It's never been like this and it feels wrong.

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.

Is this what a virus would look like?

How can I get rid of it?

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?

Any advice would be helpful. I'm kinda freaking out. Thanks!