What is the difference between implantation bleeding and break through bleeding after an anovulatory cycle? next period due next week brown discharge

Breakthrough : Breakthrough bleeding is a mid cycle bleeding in users of ocp as attributed to low estrogen. This occurs due to endometrial shedding. Implantation bleeding is the bleeding when a fertilized ovum implants in the endometrium and hits a vein in the process. Breakthrough bleeding can range from spotting to a heavy bleeding. Implantation bleeding could range from spotting to a uncommonly light period.