My Period Started To Be Very Irregular At Age 34

My period started to be very irregular at age 34 like once every 6 month or sometimes every 9 month. I checked my hormones level at that time and it was ok. Doctor said it may be stress. Now I am at 42 and I had my last period nearly a year ago. checked again because I have enlarged thyroid and doctor told me my hormones are low and I have early menopause. Is this true? I am 20 kilograms overweight. What do I need to do to check if this is true