Irregular cycle

lu

I’ve had my period for 6 years now and my cycle is still outta wack. My calandre says I was supposed to start 5 days ago and I completely skipped over my predicted period. I’ve never had sex or anything so that’s not the case and my mom doesn’t agree with taking birth control even though I really want it just in hopes of having a regular cycle. Is it normal to have a very irregular cycle at 16 y/o? And is there any way to help fix it?