i was on zafemy then i got switched to xulane and my period hasn't started

hello! i’m starting to worry because my period hasn’t come yet. i was on zafemy for 2-3 months (i can’t remember) and then got switched to xulane. i change my patches at the same time on the same day. i use a transparent cover over it so it doesn’t come off.. is the xulane the reason my period hasn’t started? on my zafemy it would start as soon as i took my patch off. i’m getting worried.