So I’ve been on

So I’ve been on them since I was 18. That’s about 4 years now. Up until last month, I always got my period during the week of the placebo pills. About 5 months ago, I switched to mircette, which has a shortened time that the pills have no hormones (3 regular weeks and then one week with two pills that have no hormones and 4 pills with lessened hormones). Last month I didn’t get my period until after I was back on the regular pills and then it was very very light for two days. This week I’m on the placebo pills again and nothing’s happened so far. Should I be worried?