4 days PP, help!

Autumn • Mommy to Bentley, and Rylee Ann on her way. ❤️
Okay so I'm not sure how to put this. I gave birth 4 days ago & I only tore on the inside which only required one stitch. I've noticed the last couple days that when I fart, it feels like it's coming from my vagina and when I have a bowel movement, i get a lot of pain down where the stitch is. Once I pee after having a bowel movement, there's little pieces of what looks like poop but in my urine? My pads are also getting filled with what looks like sticky brown poop. I called my doctor and the nurse said that it's not poop, just blood turning brown but I'm worried because I've heard of getting fissures, and I'm not sure what I should do. I try to make sure I clean myself well after urinating, and when I do have a bowel movement now I always take a shower after. I'm just confused and in pain so I'm not sure what to do or if anyone else has ever experienced this??