advise please

hey ladies, long story short..i had the depo jag in September (never wanted it was given it during miscarriage) my periods were regular on 28th of every month until the jag, they then changed to the 10th...however this month from 27th when I wiped I got really red blood just once, then nothing, then next day red again, now today it's very light brown and hardly any?? could this be implantation bleeding or is this my body maybe returning to it's normal cycle??