Does Flucloxacillin Intake Cause Rash On Body?

i was on flucloxacillin around one month ago, and around two weeks ago developed a rash around the pupic area and bum. I have been back to the doctor who has given me another dosage of flucloxacillin however i am wary to take it as i know one of the side affects is a rash. my partner now also has the rash. should i continue to take the anti biotics?