What Causes Spotting Before A Week Of Menstruation?

Hi I have been taking Noriday for just over a month. My period was for about 8 days. I have just started spotting a bit (6 days after period) Is this normal. Will it continue? I have not been on contraception for about 5 years due to fertility issues. I have a 13 month old but noticed my periods have become very heavy with clotting over the last year or so and was advised to start Noriday (not required for contraception as I dont believe I will get pregnant without fertility treatment again) which will help with the very heavy period. This first period since taking noriday was medium with almost no clotting but it just lasted a lot longer but at least it was manageable. What can I expect on Noriday? I am 42 years old. Thanks