Hi and thanks for your question. At the age of 23, you are in the peak time of your fertility. Irregular menstrual periods at this age are usually based on hormone imbalances that may occur during any woman s menstrual cycle. There is a delicate balance of hormone levels that must be maintained for normal menstrual periods. Duoluton is a synthetic progesterone derivative where the progesterone molecule has been chemically altered to act like progesterone. The generic name for Duoluton is levonorgestrol which is contained in many birth control pill preparations. The function of progesterone (or a synthetic progesterone known as a progestin) is to maintain the lining of the uterus. When progesterone (or a progestin) levels drop, menstrual bleeding occurs. For treatment of irregular bleeding, a synthetic progestin like Duluton needs to be used for a prolonged period of time. In these instances, I will use a synthetic progestin for 2-3 months. This will thin the lining of the uterus, similar to a D&C done for abnormal bleeding, but avoids a surgical procedure. Unfortunately, this does not address the underlying cause of the irregular bleeding and simply masks the symptom. An evaluation of menstrual cycle hormone levels, ultrasound and possibly a hysteroscopy may be required to find out the cause of the menstrual irregularity. If you haven t already, see a gynecologist that is well versed in management of hormone levels and evaluation of irregular bleeding cycles. If you can find out the cause of the menstrual cycle abnormality, that should help if and when you decide to attempt pregnancy. A 21 day course of Duoluton will help suppress your bleeding but once it is stopped, the irregular bleeding may continue. A 3 day course may simply increase the bleeding irregularity. I hope this helps answer your question. If you have further issues, I am available for follow up questions.