Period is roughly 8 days late and pregnancy is ruled out. I don't know what can be wrong.

I am 41 years old and had regular periods up to now. I normally get PMS sypmtoms about a week prior to the period. I have been having PMS for over 2 weeks now with no blood. I have visited an MD who ordered, after hearing of my concern about menopause, an FSH test. I read that this test must be taken on the 3rd day of the period, though, which I have not gotten. I'm not sure what to do. If I am experiencing menopause I really would like to confirm.