Should i be concerned or not?

So in the last year my cycle has ranged from 28 days to 33 days long. 30 days has occured most often and only 33 days once. I do not take any hormonal birth control and have been having unprotected sex with a man who has told me he had a vasectomy 5 years ago. Today is day 33 of my cycle(for the second time) and no sign of a period yet. Should I be concerned yet?