Start of period or implantation spotting?

so i had my period from october 27th to september 13th. it was longer than usual due to being on a steroid for a lung infection. im 20 years old, on the mini pill and use condoms every time i have sex. Since my period ended over a weekish ago, i didnt think it was gonna show up on my normal cycle day. ive been kinda bleeding this and then dark brown since yesterday (the normal day i should start my cycle). could this be an indicator that im pregnant or is it just the start of my period?

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Periods usually start at the beginning of teenage years, its new to say it starts at 20 years old.