I Am 41 Years Old And I've Never Had Children.

I am 41 years old and I've never had children. It has been 38 days since the beginning of my last period. I have taken 2 pregnancy tests 2 days apart and I am not pregnant. Am I going through early menopause? I'm not young but I seem too young to be going through this. I have been having night sweats for a year now and my doctor says this is normal for my age due to hormonal changes. She doesn't know about the irregular periods yet. Last month it was about 35 days. What is going on?