question?

Hey everyon lol, Im 15 and I got my period a year ago and it's still irregular. It will disappear for like 2-3 months then come back. Is this normal? How long until I should tell a doctor? I don't have a close relationship with my mom or dad, my friend whose had hers for years now says it's normal for about 2-3 years,  her dad is a doctor. I only want to tell my mom if it's serious bc I don't like talking about these things with her. Thanks 💕