How To Confirm Menopause?

I thought I might have gone through an early menapause. When I started taking humira for psoriatic arthritis, menstruation returned. It was a shock as it was so painful and exhausting. I stopped taking Humira a year ago due to poor liver and kidney tests. Suddenly menstruation has returned. Could it be stress related, or is this just peri-menaupause. I will be 43 next month. Thanks.