What Causes Dark Vaginal Discharge While On Trinessa Pack?

Hi. I have been taking trinessa for over a year now. About two months ago I missed starting my birth control on Sunday like I usual do and ended up starting on Tuesday. Becuase of this my period got pushed back a few days. To make up for it, when I period started on Friday I started taking it on Sunday again even though I just started. I did this hoping that my period would go back on schedule. Now, I according to my trinessa pack I am not supposed to get my period for another week but i had dark discharge yesterday and now bright red bleeding, as if I have my period. Could I be pregnant? Could it be implementation bleeding? I have not skipped a pill and do use condoms but worried if it is from precum before the condom was put on.