lolno.
There are 50 states in the United States. The term "commonwealth" has no legal impact here and was created during the colonial period to show a government based around the common consent of the people rather than the monarch of Great Britain. Hell, Vermont uses the term "commonwealth" multiple times in it's constitution.
A state is defined as "a nation or territory considered as an organized political community under one government". Seeing as how the four commonwealths are territories of the federal government and each commonwealth has an organized political community under one government, they are therefore a state.