Blood in babies poop?

My son is 8 weeks and he’s had pure mucus poops since day one. Doctors don’t give a crap and won’t help. I’ve cut out dairy. But We’re 99% sure his poop problems are from lactose overload and I have way too much milk and he has a lip tie so he can’t latch deep. Anyways. This kind of looked like blood? I don’t know it was a weird color? Is this blood? I cut out soy too but I may have accidentally consumed milk or soy. So is this blood? This color has happened twice now and I’m unsure cause my daughter has a milk allergy and her blood was very noticeable and distinct so I’m unsure what this is.