Ok woke up thismorning and there is no more bleeding at all?????

Rhi... i had my period bout 2 1/2 weeks ago so am guessing the 14 days between periods... but i am not rying to conceive atm as i have the IUD Marina in.. i got that put in on the 20th Dec i have made an appointment with my doctor for tomorrow.. i am just so confused to why i had that much blood and that bit of tissue its bizzare and scary at the same time....