The site to check your Capital One points is: https://www.capitalonepointsrewards.com

I was always looking for how many points I had on my capital one credit card account area, but could never find out how many points I had. It turns out that when you log-in to check your account, there's a pop-up which has a link to your points account. I use FireFox so the pop-up was always blocked and I never got to see it.

You have to sign up for an all new rewards points account which is completely separate from your usual capital one account, which is a hassle. It'd be better if you could check all of your account information from one place, not two.