This is one of the most common questions i get ask by patient. Diagnosing menopause can be tricky because it is a gradual process. Contrary to common belief it is not possible to do a blood test to tell you if you are starting menopause or not. Changes in blood levels will only be evident after menopause has happened and that is not very helpful because the vast majority of women feel unwell before than that and when their blood test is well within normal level. In medical terms we call this a retrospective diagnosis.
You really should not worry about pinpointing the exact time of going through the transition but you should worry instead about how the process is affecting your health and quality of life.