How Do I Know if my MacBook Pro is Using WPS?
If you simply option click on your Wifi icon on the menubar in OSX you will be rewarded with a wealth of information about the connection. - if you see something you don't like then as Lyken says log into your router and change it after,



Once you have determined the Security settings for the network you have joined, you can decide to not use it or connect over VPN or perhaps get the administrator of the modem to change the security.

Also, there is a Wireless Scan tool built into Mountain Lion and it's called Wireless Disagnostics.

You can find it in /System/Library/CoreServices (use the finder's go to folder menu item in the "go menu"). Once you open the program, you can choose the utilities window and run a scan of networks to determine their security even before you join them: