Have you been to your doctor?
I am sorry you are scared, you should really go and see your doctor as soon as possible if you have any sort of bleeding or unexplained pain in pregnancy, it is not normal to bleed heavily especially not bright red blood, the cramping is a bad sign and so are the clots, it may not be a miscarriage but it does sound like it is a strong possibility, I hope everything is ok for you, but please go see your doctor as soon as possible, and if you cant get an appointment, go to your emergency room. all the best to you hun :)
I'm sorry to hear about the bleeding and cramping. I had those same symptoms my first pregnancy and I ended up miscarrying. Usually if there is any cramping associated with the bleeding then the baby is at risk. You need to contact a doctor asap.