My 1998 Suzuki Swift is making a rhythmic banging and it shakes and vibrates my entire rear end?

So i pull out of a parking lot and going slow I've noticed it makes no noise, as soon as I start to pick up speed it starts with this banging and vibrating, enough to shake my car. I sounds close to a flat tire, so I pull over and check it out and nothing is wrong with my tire. So I figured it was my bearings. So I get home and pull my wheels, check my bearings (It's a FWD vehicle so the rear has no axle) and they're fin. The parking break drums are good, nothing's lose, all is as it should be. Shocks are fine along with the rest of my suspension. So I check the axle drives in the front, and while the rubber seal is broken by the wheels they rotate fine and all is as it should be. I cannot for the life of me figure this out. Any help would be much appreciated. Again it's a 1998 Suzuki Swift. If it helps you it's basically a four cylinder, 2 door version of a Geo Metro.