Haven’t had my period in 48 days and counting :(

I recently turned 20 in April, never had sex and never on any birth control pills etc. all my periods since young were regular! If not, they are sometimes 7-10 days late, they usually come every month anyway. I’m a little nervous because I’m not sure what’s affecting me? It’s probably stress from uni + applying to law school and to some extent my personal life? And I’ve gained quite a bit of weight lately. Anyways I just need some help and advice, I’ve been kind of worried lately :(

Edit: I had a very light period a couple of days after posting this! So all good :)