Welcome!! Others with more experience in the "young child" department will be along- although it might be a little slow today, being a holiday.
Just my 2 cents- I can't say your child does or doesn't need a therapist or anything else, but I don't think I would cast a diagnosis of ODD on a 3 year old when it was made by a pediatrician who only saw one aspect, one time, in one situation. Again, there very well might be something going on with your child, but don't lose sleep over an ODD diagnosis just yet.
