Is it really worth getting a security program for Mac?

I got my MacBook Pro 6 months ago, and my Kaspersky subscription is about to expire in a few days.

I've only ran into viruses, malware, etc, 4 times since I got my Mac in July 2013. It's obviously now January 2014.

•Once when I was looking up school info
•Once when I was trying to download a song
•Once when a stupid pop-up window appeared and automatically downloaded a "security program"
•Once when I was looking for a Minecraft mod.

So is it really worth getting a security program?
Even if it's a free trusted program like Avast or AVG?

For me, four times is enough to keep the security program. You paid a lot of money for your MacBook Pro, and you want to keep it running at its best. Also, think of the time you'd spend and the aggravation if you had to manually fix malware yourself. Some malware keeps you from moving forward or backward a page, and keeps you from turning your Mac on or off. If you get that you're pretty much stuck.
I'd keep your Kaspersky. You can get a free 30 day trial of Kaspersky Internet Security 2014 for the Mac at the Kaspersky website http://usa.kaspersky.com/downloads/

Better safe then sorry. Mac's are slowly becoming more of a target for virus's and malware. Http://www.avast.com/en-us/free-antivirus-mac