New here! TTC for 8 months

Amy
So I have two questions. Here is my first. I have always had this question and never got a straight answer from friends or family. 
Is it normal to have four days of normal bleeding, two very heavy and then one or two days of very dark almost brown spotting with a strong Oder and then a few days after of lightly browned discharge with a strong Oder? This has been to be the norm for me for years and my Doc always says its normal but never gives me a reason.