This is how it happened:

I was going 50mph through an intersection and it is one I never used before.

This road I crossed over was higher up and made my car almost launch like a jump ramp.

A lot of the weight of the car pushed upward and then fell making the suspension work hard.

After I hit this bad part of the road, the car of course was slowed because I let go of the gas.

Now I am doing about 40mph so I wanted to get back to the 50mph speed limit.
When I pressed the gas, the car felt like I was going over a scarred road, in other words there was a vibration that I felt from pressing the gas lightly. The road was fine and had no such rough areas.

I let off the gas and it immediately was gone.

I then pushed the gas the same way and it made that odd vibration that could be felt and heard.

I let off again and of course no more vibration.

The next time I pressed it, it was gone. It never did it again, and I am VERY curious on what could have made this happen.

I did not bottom out, I did not hear anything hit, feel it get hit and on top of it I pulled into a gas station and looked thoroughly under the car and did not see anything.

I have 12,500 miles on the car, and never had this scenario happen before, nor have I had that noise happen from pressing the gas.

I am a little worried here, any idea what might have happened?

I hate having a new'ish car and have an incidence such as this cause a wierd reaction and not know what it could possibly be. I have had with other cars where I have accidentally been in a similar situation, but never had odd vibrations from trying to accelerate right after.