Thump noise from front end

I just replaced all the struts on my 98 cavalier and i've got a strange thump sound that comes from my drivers side front tire. I replaced both the strut bearing plates in the front of the car and still no change. I realze i need an alignment but i don't think that that could cause the Thumping sound.
I put monroe sensatract on the front and gabriel ultra in the back. I used the original springs and all the rubber bushings that were at the ends of the springs.
The sound starts up at about 15 miles an hour and disappears at around 45 - 50. Has anybody experienced anything like this?

i did, it was a loose caliper....i can't confirm your case though

Thanks for your reply, but everything checked out ok with all the parts but the bolts. I Took my car up for an alignment and they had a surprise for me. the car was so far out of alignment that the tires themselves were making the noise. Apparently you can't just use the same mounting bolts that were from the factory with the monroe struts. You have to use camber bolts, which are a bolt with a narrower shaft and a lobe on them to push the top of the strut farther out so that the camber can be aligned properly. so now the problem is gone and onto other issues.

Thanks for your reply, but everything checked out ok with all the parts but the bolts. I Took my car up for an alignment and they had a surprise for me. the car was so far out of alignment that the tires themselves were making the noise. Apparently you can't just use the same mounting bolts that were from the factory with the monroe struts. You have to use camber bolts, which are a bolt with a narrower shaft and a lobe on them to push the top of the strut farther out so that the camber can be aligned properly. so now the problem is gone and onto other issues.well there you go ,good info to save for future references