What Causes Brownish Discharge After Menstruation?

Hi! I just had my period last Feb. 22 and it lasted for 6 days. Yesterday I have a brownish discharge that has smell. Today more brownish discharge in the morning and during noon it became blood (small clots) and in the afternoon I had a light red discharge. I m feeling a little stomach cramps just like I m going to have my period. What do you think is happening? Do I need to see my OB Gyn so I can be check? I m 47 years old and I still have regular periods 28 days cycle.