Did you not discuss your changing periods with the doctor? It sounds very much like you are entering perimenopause, a time of unknown length when our bodies begin to produce less estrogen and throw our cycles into a bit of chaos. What you described is perfectly normal for perimenopause. Sometimes we skip periods, the next month we have 2, the month after that we bleed heavily for days, wondering if we need a blood transfusion, then we have two month of nothing but spotting..............it's great fun wondering what our bodies will throw at us each month. True menopause is reached when we have gone an entire calendar year without a period.
You were diagnosed with a vaginal infection and treated. I hope it was a simple yeast infection and the antibiotics cleared it up. The brownish colored discharge is usually just old blood mixed with the increased secretions of an infection.
You asked for advice so I will suggest you see your gynecologist to discuss the changes in your periods, a blood test can determine if your hormone levels are dropping which will indicate perimenopause. You can get information on what's in store for you and discuss HRT and other options at that time.
Just remember that menopause is NOT a disease or a disorder that requires medical intervention. It is a natural right of passage for all women.
If you have more questions, please feel free to post again.
See your doctor.
Peace
Greenlydia