Please Help me Out!!!!! Health Problems?

Today I noticed my stool contained alot of blood, it was a mixture of bright and dark red….and 2 more bowel movements contained blood clots but not as bad as my first one…The last couple months Ive noticed constapation and dierria…I am often fatigued and out of breath….I went to the doctor and she gave me a rectal exam and she said it didnt contain any blood, she recommended me getting a colonospie….Iam afraid it might be colon cancer because it seems I have alot of the symptoms, my dad has digestive problems such as polpyps and it runs in the family….can anyone give me some advice??? or any clues what it might be?????