phatso - there is no limit to the number of characters you can type in your message. Feel free to use all the words you want and include all of their letters - after all, the words earned them!
As to your problem, it is more common than not for a female to have irregular menstrual cycles. Birth control pills will help regulate a period (after about 6 months of use and if taken properly), but even they don't make the menstrual cycle behave in the clockwork you seem to demand. Stress is a major contributing factor in delaying the "flow" era of the menstrual cycle. If you are behaving with her the way you are behaving here, I can assure you that she is feeling stress.
If you are truly 18, that makes you an adult. Ges itz tym to strt behavn lyk 1!