Weird question about my brakes

[brainless twit]

I'm not sure if something is wrong or if I'm crazy. I'll try to explain this the best I can in my non-technical way.

The other day I was pulling out from a four-way stop and another car ran the stop sign. I had to slam on my brakes to keep from hitting the other car. When I did, there was a sound and sensation like a spring uncoiling. The brake pedal felt really strange under my foot. After I kept going, I didn't notice any problem.

On Tuesday I was traveling on a highway doing about 60 mph. I came over a hill and there was a wide load tractor trailer coming through, so I had to stop quickly and pull to the side of the road. I didn't exactly slam on the brakes like before, but I hit them with more force than I would for a normal stop. I felt the springing again, didn't hear the sound, and my rpms shot up and quickly came back down.

I may be paranoid, and it may be the ABS kicking in or something (my other cars didn't have ABS), but now I'm terrified that something is wrong with my brakes! Can anyone explain what this is? I know I didn't describe it well but I don't know what else to say about it.

I'm going near the dealership where I bought it today, but they aren't very pleased with me because I didn't rate them well on the Toyota survey. The manager actually called me demanding to know why I gave them a low rating on a certain question when they specifically "told" me they needed an excellent rating. Um, well, because my car broke down on the side of the road, I called the dealership, and no one called me back for over 5 hours. I had to call another dealership to have it towed in and repaired (water in the fuel tank, gas station had to pay to have it fixed). So no, I wasn't going to give them an excellent rating when no one even responded to my call. Anyway, that's a whole other post. I don't want to take it in if I don't have to, but I want to make sure nothing abnormal is going on.