Hello, you are finding unclear answers because it is very likely that the requirements are company specific. For instance one preschool may require certification or a degree and another may just require a number of years of experience. In the state of Oregon you can teach preschool without certification or a degree in some centers. It is not like elementary or secondary education where a degree and license is required. You may on the other hand find that specific schools require their preschool teachers to be certified in my opinion and understanding this is more of a selling tactic to the parents rather than a state requirement. Three years is a lot of experience in the field of preschool education, you should be able to start looking for jobs and you may inquire if they would assist you in obtaining certification while you are working for a school as a teacher.

If you found my answer helpful please remember to accept as this is the only way I am compensated for my time. I am happy to answer any additional questions.