Car will not move when in gear

I had just replaced the clutch, throw-out bearing, and the fly wheel because the car would start but when I would try to shift the car into gear it would not move and I could even let up on the clutch completely without touching the gas and the car would not stall out. After I replace those it has worked for about a week and now the same thing is happening. Also I don't know if this is relevant but when I have the car in gear and press on the gas even though the car does not move the speedometer acts as if it was moving