I use the nuvaring but the past month I ended up leaving it in one extra week. Also during that month I was on 3 types of antibiotics for food poisoning and a UTI and had a shot of antibiotic 5 days ago. 4 days ago I had unprotected sex and today had a brownish/pink discharge on my panty liner. Its been a little over 2 weeks since my last period. Is this implantation bleeding, moreover could I get pregnant under all these conditions?