Menstrual cycle over the 3 weeks and continuing but not like my normal cycle brown but its light and occasionally have deep dark red blood clots?

Abnormal cycle. There are many reasons why you can have an abnormal cycle. When you have one that doesn't occur during the predicted time frame, pregnancy needs to be ruled out. If the pregnancy test is negative, then you may want to be evaluated by a gynecologist to figure out what is causing the abnormal bleeding pattern. Infections, medication changes and abnormal tissue can cause changes in your cycle too.