Did i get my period ? Please help & Not first period?

Not my first period , i am 16 I`ve had them for 4 years! i was late 5 days and on birth control pills . i went for a pap smear on friday & my doctor told me i got my periode just very light but it was brown which i tought was weird it only lasted like 10-24hours that's all and i am scared! i have real bad back pain tho its baddddd i have a hard time sitting down .