birth control

i'm on my second week of birth control and i started it 7 days before my period. my period did not come and i'm assuming it's because of the birth control but this morning i started bleeding it was very light only a slightly different colour than the toliet paper a brown tint when i wiped but now it's picking up it is not more heavy still not filling up a panty liner but there's a lot when i wipe and it's more red/ pink in colour is this spotting or my period? or implantation bleeding?