What Causes Reddish Brown Vaginal Discharge After My Periods?

hi, I woke up this morning and noticed my underwear was covered in blood, it was a reddish/browish colour and when I went to wipe there was chunky little peices of jelly looking things.. and I'm a little confused as of how this is happening.. I finished my last period normaly and I'm not due for another in two weeks, I don't know whats happening, could it be a misscarrage?