While my doctor told me that it was normal to have some bleeding/spotting during pregnancy, passing clots of tissue does not seem normal. I would see your doctor as soon as possible and ask for an ultrasound and a blood test. The urine tests are less predictable. I hope it everything turns out well for you!
Hi there and I'm sorry your feeling so scared. There are a couple of things I want to point out. First off, the PT that tells you how far along you are is a guess at best. It is not possible to date a pregnancy any other way then an ultrasound really. What those tests do is try to measure the amount of hcg in your urine. There is a huge range in terms of how much you should have a various times in your pregnancy, so while fun, they should not be considered accurate. Also, home tests are often far more sensitive then Dr.'s tests (yep, it is true). Time of day can also make a difference as to how diluted your urine is, producing different results. So it's possible to get a positive in the am, then a negative in the pm in early pregnancy.
The bleeding is not so much a concern as the clotting. Although never considered normal, bleeding in early pregnancy is common and much of the time things turn out just fine.
I wish I could tell you for certain what is going on. I am a little irritated with your Dr. for making you wait. What should have happened is two blood tests about 2 days apart. Unlike urine, blood will give you an accurate measure of your hcg levels, and having two of them a few days apart can tell you if they are rising at a decent rate or not. It may be a bit early for u/s to be definitive or not. In any event, I hope you get your answers soon. I would say right now it is 50/50 and I know how hard that is. Take care and all the best to you.