Started my car up this morning and let it warm up started driving to school and when I was getting on the freeway it suddenly started making this clunking noise and I could feel it through the pedals. so I immediatly pulled off the free way and checked for rocks or something but found nothing. Did not know what to check so I put my hand on the UIM and could feel the vibrations through that also. I then decided that i was going to slowly drive it back to my house, so I get on the freeway and when i get up to speed (45) the clunking is gone. When I get off the next exit to turn around when I slowed down it started up again, but once I got back on the freeway to get home it dissapeared and when I got off the freeway where my house is the noise was completely gone. And it was driving normal. I know i need a new clutch because my bearing is making noise, could it be related to this? or engine problems?

Any advise?

thanks