Spotting before period.

Last month I began spotting 3 weeks after my period. (I thought it was implantation bleeding) but then 4 days later I started my period. (So pretty much a whole week early). 
This month I began spotting again. This time it's 3 days before my period was due. (I'm suppose to start tomorrow). 
I've never spotted like this, and for so many days before a period before. 
I recently came off the pill in June. That's really the only thing that's changed. So this has happened for both October & November. 
Thoughts?