Heavy period.

My period came 7 days late... i was hoping it meant i was pregnant! But then AF came on the 8th day.. started as light spotting.. now it really heavy.. i normally have heavy periods, but nothing like this one.. everytime i stand up ir go to the bathroom theres several blood clots.. my cramps were worse yhan my normal ones..last night i woke up with a really bad stomach ache.. felt like i was going to throw up.. i could feel a clot coming.. it was really big.. never had one that big before.. has this happened to anyone else??