What are symptoms of belt slippage?


I make a smooth brisk take off, after it shifted to 3rd, there's this jerk as if the rpm dropped for a second almost like shifting to 5th gear. And then, everything's back to normal.
This has happened three times now, usually as I drive out in the morning.
I normally run the motor for a minute before I drive out of the garage. The exit is a mile away, so, by then the motor has warmed up completely.
Although, the same thing happened one time at a much later time of the day at a much higher speed (accelerating from 60 to 70 quickly)
Is this a result of having the C3 pulley?



