I'm 44 years old and my period is 2 weeks late, my partner had a vasectomy 8 years ago. Could I possibly be?

I know a vasectomy is like 99% accurate, could I be in the 1% and be pregnant? Do you think I am starting menopause? My periods have been very regular until this month, have been experiencing hot flashes on & off for about a year. Should I take a HPT?