Over the past month ive had slight breast tenderness which I thought was a side effect of my Nexplanon implant which ive had for over a year now. But I've noticed my breasts have grown since, not massively but still enough to notice. Now the pain has gone and I have 3 blue veins on my left breast. From what I can remember ive always had one there anyway, but the sudden changes have got me worried.

Could this just be a mixtue of late puberty, as I'm only 18, and hormones from the implant? Whenever I google it, it mentions pregnancy which I panick about, but surely with the nexplanon having a 0.05% failure rate it can't be that?