It can take up to 3 weeks for a plant to produce primordia/pre-flowers after switching to the flowering cycle.
Your plant needs to go through massive hormonal and metabolic changes to initiate flowering, something that takes time and can in no way occur in 2days. Be patient, it will happen, but not overnight.
If you are keen, go to my diary "cannabis conundrums" and in week 7 you will find pictures of male and female primordia, this may help you identify what your plant is doing. There are also many other pictures of weird and wonderful things that cannabis plants are capable of doing.
Hope this helps,.............
Organoman.