depo provera

chloe
hey, so ok my boyfriend and i have had unprotected sex right. i've been on the shot since june 27th i believe. 
so it started out totally ok, but like today we just had sex again and i started having really light blood, like yeah and then i checked with a tampon to see what was going on up there and there was like legit blood??? the only reason i'm asking is because we had sex 12 days ago and that's within the threshold for implantation bleeding. 
i'd just like to know everyone's experiences or thoughts i guess. idk i'm just spooked. 
thank you!