Scared I have bowel cancer :( I’m only 22

So I am a 22yr old male and I have had ongoing symptoms for quite a while now, been having back pain and abdominal pain, was a period where I had a change in bowel habits but now they are back to normal but the scary thing is I have bright blood in stool for 3 days now, had a exam of my rectum and I don’t believe I have hemorrhoids, sent a stool sample and waiting for results, I am having a blood test on the 7th and I’m just really scared. What Else can bright blood in stool be?