What could be the cause of three nose bleeds in the last two days and today a blood clot came out while your nose was bleeding and should you worry?

It could be because of dry air. If your nose gets dry, the membranes burst which causes your nose to bleed. It looks like more blood than it actually is. The clot is what should happen. Since it came out, it may bleed more until it clots again. If you are still concerned, see your doctor.