Blood clots or miscarriage?

****Sorry if this is TMI, but I'm starting to worry if I need to make a trip to urgent care***

Does anyone know how to tell the

difference between big blood clots from a normal but just really heavy period and a potential early miscarriage? I've gone through 3 super tampons in the last 4 hours and I've passed 3 silver-dollar sized blood clots in that same time span. My husband and I have been TTC for almost 3 years and we did the baby dance several times in my fertile window. Plus i was 2 days late on my period.... well now aunt flow is here with a vengeance and punching me in the uterus. Should I be worried this is more than just a really heavy time of the month?