Late period

Hi guys, my period is late by 21 days... I'm a virgin so I know im not pregnant but I'm still a little worried because it's never done this for so long; it's always on time. Recently I'm really really stressed-- just in case that has anything to do with it... I'm personally not complaining because I hate having my period 🙄 but I just want to make sure everything's ok. Is it normal? Should I go to the doctor?