What Are The Side Effects Of Implanon Birth Control?

I have been on the Implanon implanted birth control for two years now and have not even had a single spotting(of a period). Now today all of a sudden I am spotting with what I assume to be a period. Is this normal(after TWO whole years?) or should I go to the doctor? I have also made many other healthful changes to my life like cut out smoking and drinking, which I used to do daily. Could this be the birth control or just the other changes I have made in my life? Should I see my doctor?