My period became irregular??

Hey guys I know I need to make a doctors appointment but I’m starting to freak out and I need some opinions.

Ever since I got my period it’s always been five days now recently a few months ago my period keeps reoccurring I’ll get it for like 7 days and then maybe a week will pass and I’ll get it for another 3 I’m not experiencing a lot of unusual pain or anything like that but it’s still concerning. At first I thought maybe hormone changes but now that it keeps happening I’m getting worried because it’s like there no time for ovulation in between me getting my cycles please give some advice 😭 I’m 21