Novelon is a oral contraceptive
pill which contains both estrogen and progesterone(ethinyl estradiol
0.03mg, desogestrel 0.15mg). There is some evidence that long term estrogen tablets may cause breast cancer
. It is more so if any of the relatives have breast cancer.
But in case of irregular periods
it is of relatively low dose and duration less.
You can continue using it nothing to worry