breakthrough bleeding or implantation?

I've been on birth control for a year now and it's low dose (lessina) I've had breakthrough bleeding on and off all through out the pills. 2 months ago I breakthrough bled for a couple a days, last month I didn't. But what's scaring me now is that today when I wiped I had clear discharge with traces of blood and after a second wipe it went away. I have 3 more pills til I'm supposed to get my period. I'm only 18 so I'm scared right now and I also take my pills everyday within a 30 minute window never missed one. Please help with advice