bleeding randomly on the pill? 2 periods in 1 month

Ci
Ugh girls so I need help! 
I started my period at the beginning of the month and now I started my period again :( so twice in one month and I am on the pill I have been on the pill for years (OrthoTriCyclenLo) and occasionally I'll take the pill an hour late or so but I have never experienced bledding like today :/ I know it's not an STD I always get checked but what could it be? Help 

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