What will be causing me to spot for two months? I'm not pregnant. I'm on birth control.

Possibly wrong pill. If you have been taking your birth control pill daily and not missing any pills, it is most likely that this pill isn't the right balance of estrogen and progestin for you. Also, make sure you are not on any other medications that would interfere with the birth control pill. Discuss with your provider other brands that may be better.