Am I am 35 years old and have not had my period for three months now. I wanted to know if menopause has began?

This is a question only your doctor can tell you definitively.

However, you are in the age group in which some women become perimenopausal. Perimenopause can last up to 10 years before full menopause sets in.

For menopause to be considered you have to have not had a period for a year.