Hi!
If you were my patient, I would advise you that if your period is overdue, there is a chance of pregnancy and you should do a test. I would also remind you that there is emergency contraception available--Plan B and Next Choice are two different options. These tend to give you a little more peace of mind.
Good luck!
Dr B
The pull out method isnt a reliable form of contraception (but hey, apart from abstinence, what is?) I was on the pill when I fell pregnant. But given that your periods are irregular, I would take a test... If negative, them wait a few more days to test again... Stressing out can delay your periods as well. If positive... Then congratulations :-) x