Suggest Treatment For Irregular Menstruation

On loestrin 24 for about 3 months. throughout the past months, i've gotten my periods normally ( 5 days about and usual looks of blood) I usually start my periods the 25th of each month. this month ( june of 2010, ) i had (in the middle of the month) a 2 day very light blood that i only got when i wiped to use the bathroom. so nothing big at all. it is now the 30th. what is going on?