This is negative right?

Little context- I switched birth control pills about 2 months ago, and started having sex with my boyfriend at the beginning of January (so start of the 2nd pack) and we've also used a condom every time. I've had brown (kinda pink at first) spotting the past two weeks (the week before and the week of my placebo pills) with a little bit of red and a little heavier this past week. Just wanted to check if this is just my body getting used to the new birth control or if it's implantation bleeding? Thanks guys!