NEED ANSWERS FAST PLEASE!!! Hello Doctor My Girlfriend Is Currently

NEED ANSWERS FAST PLEASE!!! Hello Doctor My girlfriend is currently taking Lo loestrin Fe 1-10 and this is her third month. She takes it everyday between 9:00-9:05 PM. Recently however she began having the FLU and developed an ear infection and was prescribed a 125 MG tablet of amoxicillin or Amox/clav 875 for ten days twice a day to help with the infection. I asked her doctor if in anyway it would interfere with the birth control and he said it should be fine. My girlfriends last period was from the 9th to the 11th of April and today after her second day of taking the antibiotic she experienced some spotting. Her period is supposed to come back on the 7th of May but I'm worried because breakthrough spotting is something that needs to be reported especially if taking birthcontrol while on antibiotics. We had unprotected sex yesterday two times without ejaculation ( the preejaculate might have had some semen) and I'm worried that something might happen. I don't know if she should maybe take plan B or any of the measures she should take for our protection. Apparently spotting is common in the first three months of Birth control but I'm Still worried please help your answers would be much appreciated thanks so much.