Hello. I am 24 weeks pregnant, and for the last couple of months, I have noticed some changes in my stool. Sometimes it is dark and almost black, a couple times it looked like there was something red in it (and not sure if it is just something I ate such as twizzler), and a couple times after a firm stool has passed, when I go to wipe I notice a brown stringy type thing that almost looks like brown vaginal discharge, but it is coming from the anus. Is this fiber undigested, possible hemorroid side effect, or something more serious?