Brown residue? With clob

I recently got prescribed clob but got no instructions from my doctor. I’m waiting on an OBGYN appointment where I’m assuming I’ll get more info.

Not every time, but sometimes when I use clob at night and I wipe in the morning I have a brown residue on the toilet paper. I’m nowhere near my period. I can’t tell if it’s residue from the skin or discharge. I’m wondering if this is something expected or weird.