How does one distinguish between prodromal phase of schizophrenia or is it possibly it is nothing or turns into nothing at all over time?

No quick answer: There is no short answer to the question. If there are symptoms associated with schizophrenia or any other psychological symptoms, a person should see a psychiatrist and discuss the symptoms as well as any concerns about them. It is is understandable why someone would wish that a symptoms was "nothing at all." however, such wishful thinking leads to avoiding treatment which can be helpful.

Need time: Schizophrenia is often proceeded by a pro drone phase that is most evident in retrospect after the acute phase of illness has manifested. In its midst, the symptoms of the pro drone phase are to vague to support a diagnosis. If suspected, individuals in the pro drone phase should have ongoing evaluation by a physician.