Spotting at 9 DPO?? Implantation or just irregular period ?

I’ve just had some spotting and I’ve been cramping for the past 2 days and just feeling generally PMS-y.... thing is my period isn’t due for 6 more days. Is the spotting more likely implantation bleeding or just my period being irregular ? My periods have always been regular until I got 1 Depo Provera shot in May, it wore out in August and I never got another shot (because the side effects SUCKED), so since August my periods have been wacky/I’ve been having spotting. But I thought my period was regulated now because I’ve had pretty regular cycles (normal period length, normal cycle length, with no spotting between periods) in November and December..

Other symptoms are breast tenderness and lowered tolerance to alcohol