1 tick repeater clock shows 3 ticks at first

when a one tick clock is connected to a series of redstone repeaters (all set to one tick) and the output of each repeater is connected to redstone lamps the signal is first shown as 2 or 3 ticks and then one tick. just reproduce the setup in the screenshot. place redstone wire to connect the first repeater in the chain to the clock and observe the signal output. I may have observed it to occasionaly do 4 or even 5 ticks at first.