2002 Chrysler 300 Strange Thumping under my floor

Hello,

I just bought this 300m special and when I drive on a road that's not perfectly smooth, there is a slight thumping sound under the floor in front of the drivers seat. I can also feel the thumping as well. I think that it could be the shocks, but I have no idea. It doesn't seem to affect me when driving at all, but I'd at least like to know what it is and how serious it is. My car's sensors told me to service my tire pressure system, but I think that is unrelated. Thanks to anyone who can help me with this.

Sincerely,
Jack Teed