Well, I can say that the blood in your urine will not affect the results of a pregnancy test, however the fact that you bled clots and that the lines got lighter suggest you may have had an early miscarriage. I would see a GYN doctor who can test your blood for pregnancy, which is more accurate than the urine test. The hormone level will tell the doctor and you if you are still pregnant, which is still a possibility. I hope this advice was helpful and answered your question. Take care, Dr. Brown