Worriedd??? is this normal

Okay so girls i have really bad anxiety so there this is making me more worried as this has never happened before... okay so... My period was due to end today but hasnt... My fiance was winding me up with my clitoris stimulation vibrator (ann summers rabbit ears) and it was turning me on and making me orgasm etc but then i went too the toilet and quite large blood clot came out??? Is this normal??? Please??? Im really freaking out as this has never happened before!!!!