Thank you for your question. There are several different things that can cause higher than normal rates of bleeding
during the menstrual cycle. Your story itself does provide some clues, however. If the bleeding had been continuous or near continuous since the birth of your daughter regardless of your normal cycle, then it would be worrisome for some sort of exposed blood vessel or other similar pathology unresolved since the birth of your daughter. Because it is apparently connected with your cycle, however, it would seem to indicate a change in the uterine lining. These sort of changes are often associated with other hormonal changes that can happen after pregnancy. For example, weight gain and loss can affect the level of bleeding during the cycle. There are myriad other possibilities that should be discussed and pursued with your doctor
to determine if all is well. While some of these changes can have simple explanations, discussing it in more detail with your doctor will allow you to make sure that you have accurate information. Additionally, too much blood loss can pose an added health problem in and of itself and should not be ignored. Again, please discuss this with your doctor soon.