Weird issue during braking

[xtremesniper]

I'm not sure if this is really an issue, but I thought I'd try to explain it on here to see if I'm the only one with it or not.

Basically, there are times when I approach a stop light or a speed hump where I'll either gently press on the brakes to slow down from lets say 40 to 20km/h, or just to a full stop (in the case of a stop light), or I'll let the car glide to a slower speed (and sometimes the Yaris does its own "engine braking"). During this slow down, sometimes it kind of feels like a certain part of the brake pad is tighter than the other. That's the best way to explain it I think, because you'll feel like there's a slight/subtle tapping of the brake that I'm not actually doing every half second (possibly every revolution of the wheel). It seems to only happen when slowing down from an already fairly slow speed, which is why I only feel it sometimes because I'm usually driving on roads with a higher speed limit.

Anyone know what I'm talking about? Should I go in to get this checked out?