Is blood on stool surface or just dark? Clinically, you need to be checked if you just have hemorrhoid- or anal tearing-related bleeding, etc.
since the drugs you took have no clinical odd to cause GI-bleeding. So, you may wait if bleeding is not severe and no other systemic symptoms, but please follow instructions in https://ebettercare.com/feel-become-sick/. Thereby you can work well with dr.