The suppression of blood over the years have built up many toxins in your body. A woman bleeds monthly because this is one are where we store toxins, and where monthly cleaning is essential to the natural body wanting to get pregnant.
The best thing you can do for yourself is remove the implant. Your body is telling you with huge red flags this is not healthy for it, and it will cause you continued toxins and stress to the body. YOu will continue to have blood issues until you place your body into a state that it knows how to exterminate the blood naturally.
With all my fasts I get huge amounts of bleeding and my menstrual cycle usually starts within 5-7 days without food.
If you can remove the implant and continue your fast. Your body is stating boldly to you just how toxic it is.