اجريت عملية قيصرية و بعد يوم نزعت الخيط لكن ظهر ان الممرضة نسيت خيط صغ

I think that was caused by an infection inside the uterus which caused the uterus to bleed, blood collected then the uterus contracted to expel the clots out. I must say that complications may happen during any surgical operation, I don't think what happened to you has anything to do with the good job your doctor did. In other words, it is very unlikely a fault of your doctor. I am sure you discussed what happened with your doctor who provided you with answers. Regards