Question roughly speaking cycle
Answers: I used to own the same problem but mine would be anywhere from 18-42 days. I fixed the problem by going on birth control. My cycle is now so regular, I pretty much own it down to the time of day as well as time of month!
As for a pregnancy oral exam, I'm not quite sure what the best solution would be. If you are really worried, I would suggest going to a clinic and having them do a urine exam to find out. It beats the heck out of worrying about the results of some drug store pee-stick pregnancy tryout..
i've had my period for a year and it is unbelievably screwy too. just take a pregnacy audition so you don't have to worry. Take a pregancy tryout just so you will know for sure then you can stop worrying and keep on for your period.