Strep B testing while pregnant

Trisha 🌻🦋

37wks found out I tested positive for strep B, Doctor said it’s common and nothing to be worried about I’m having a c-section! Be reading up on it && I don’t understand how or it ? I didn’t have it my first pregnancy I’m healthy, never had an STD, don’t sleep around so where this come from can’t help but worry😔