What should I do? Help

Okay so.. We are not trying for a baby right now. It's not the ideal moment and were just not ready. About a week and a half ago we had a mishap and the condom broke. We didn't know what to do. We're not ready. I took a plan B pill and hoped for the best. I got my period at the end of last month but it was very light. Resembled spotting. Today I had a bloody discharge when I wiped and don't really know what to think. I am on birth control and at the moment have been on an antibiotic for two days now. And. Not really sure what to do. Should I take a pregnancy test, or wait it out. Has anyone ever had this happen to them and have some advice?