Antibiotics, The Pill And Pregnancy? Please Help Me :(?

So I was put on Trimethoprim antibiotics because I had a water infection, and nobody told me this would make my pill (microgynon 30 if that makes any difference?) less effective! I had been taking them for 2 days when I had sex with my boyfriend (on the 1st of april) and i still have 2 days left of the antibiotics, now someones told me that its possible that I could be pregnant?! I’m 16 years old I can’t have a baby how likely am I to be pregnant? Please help I’m so scared

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