My period won’t regulate!!

I’m 14 as of right now and it’s my third year of having a period. And I never know when it’s going to come! It can start the 5th one month and then the month after it will start the 23! It makes the whole thing 10x more stressful and makes me worry about what to wear and waste pads thinking I’m about to start! Do any of you wiser ladies have any tips on how to regulate it or how long it’s supposed to take to regulate?