Last month I was down with a strain of noro virus and on a Friday I went to the ER for fluids and they gave me an IV antibiotic. The following day I got my period as normal. For the next 6 days I was recovering and had my period as normal, and not thinking anything of it, did not use any backup forms of BC. This month, I was 3 days late and only had spotting and some light bleeding. There has been a ton of stress in my life this month, and I have read that not many IV antibiotics interact with oral contraceptives but I admit I'm a little bit uneasy. Is what I've read true as far as IV antibiotics interacting with the pill?