PLEASE HELP

Hey <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> fam
I really worried because I got my period 10 days early. My last period started and finished on time. I have done nothing out of the ordinary and I'm going in a holiday tomorrow and don't have time to see a doctor. I know this isn't normal and I don't know what to do. 
I am 15 and I don't want to tell my mum because she isn't coming on the holiday and will try to make me stay home. 
Someone please help!!! I have no idea what to do.