Spotting and brown discharge

I've been having brown discharge since week 4 till now, week 15. Recently, it's more especially after I pee and wipe. sometimes it's bright red or with red/brown tissues as well.. Went for check multiple times, but the doc always said it's fine. They did mention my placenta is a bit low too so but they are not able to identify the main cause of this continuous spotting and discharge, and it's giving me alot and I mean ALOT of anxiety. Does anyone face the same situation? #firsttimemom