I am on Birth control pills. I am wondering if a plan B is needed. Last month I was on Metronidazole and fluconazole. I was finished both of those medications on the 11th. Had my period,23rd- 26. But started pink pills 24th. Sunday 22, I was put on Azithromycin and finished it 26th. Had unprotected sex Thursday night. Considering, being on my period and all the medications should I need a plan B?