brown discharge when i wiped?

okay so i’m on the pill and I know i’m not pregnant cause i’ve been getting regular withdrawal bleeds and also I went to the hospital for an unrelated reason and they took a urine test and it came back that I was not pregnant, haven’t even had sex since. a couple weeks ago, at that same hospital appointment, they prescribed me heavy antibiotics because I had pneumonia. I’ve been a little itchier than usual down there but no weird smell or abnormal discharge. today I wiped after using the bathroom and it was brown, almost what it looks like right before or after my period. i’m still on my active pills. they said the antibiotics would interfere with my birth control for a bit but the antibiotics aren’t even in my system anymore so i’m confused? should I be concerned? i’ve had no other symptoms besides the mild itching that has pretty much gone away at this point.