Bleh. I definitely remember getting super sick as a kid sometimes and I didn't go see a doctor. I went through mono not even knowing I had mono. Now I know better. If you see blood when you cough, go to a doctor. Heck, if you have a problem you feel unsure about at all, go to a doctor. I'm trying to remind myself that it's OK to see a doctor if you're sick.
Not going to see doctors and toughing it out is such a bad practice. I even know people in boyscouts who are troop leaders. It's what let my mum's cancer go undiagnosed until it was lethal. She was like "Eh, whatever, who cares if there's blood where there shouldn't be? Detox cleanse at home. No money, no doctors, no matter how bad it gets." Fast forward a long while (about a year!) and the doctors were giving her six months without treatment, 3 years with. She made it 5, but they did mention it was probably curable if they'd caught it sooner.
It lingers, ya know? It's a constant reminder of what happens when you don't get problems checked out. Now I try to go see doctors, even if I think I could get better at home if I just toughed it out, if I can then I go see a doctor. Better safe than sorry.