Urgent…..miscarrige

Patient: I am pregnant i think about 11 weeks and the last few days i have had old blood comming out this started when i had sex 4 days ago but the blood was continual but small in amounts and dark in colour until today….today it got brighter in colour and i went for a run earlier i have been experiencing cramps i dont usually get bad cramps on my period even i stood up after sitting down for a long time and i felt almost as if i had wet my knickers and then it almost felt like a drop i went to the toilet there and there was a lot of blood much brighter in colour with something in it perhaps clots but it looked lighter in colour then clots what is happening?

Doctor: