1ST Time taking Chrysanthemum Cuttings

It's as the title says, and I am following the 'book' . . .
Took the cuttings 3 weeks back, 4 cuttings to each 3" pot and pots placed in a propagator (electric with bottom heat).
All looks well and I took one pot at the week-end to pot them on to find only one had some root. The others showed no sign of rooting. The one cutting was potted on and is doing ok. I am at a bit of a loss really as I took the cuttings normally with a cut under a leaf node and dipped in rooting powder.
Am I rushing it, should I leave them in the propagator another week or so?