Abnormal period

So I just started my period a week early. I haven't been on birth control for almost 3 years now so I've been very regular but recently my period has been off track, coming extremely early or late. I have been fairly stressed and not getting as much exercise as usual so I think that might be why. However, I woke up this morning in panic because I could feel myself bleeding through a super sized tampon so I rushed to the bathroom and there was so much blood. I don't think I've ever bled so much? And there were a lot of those little blood clot things? Should I be worried?