Imagine that my friend calls me and we have the conversation while I am on my way to school (I'm walking at the moment of speaking):
-Where are you?
-I am going to school.
I know that "I am going to school" means:
1) that I'm preparing to go and I probably at home yet;
2) that I'm going to school next year (to start my education).
So how to say correctly that I am on my way to school using the verb "go" and present continuous. Is it possible at all?