Can a clot hold up your period?

So, I had pretty much no bleeding since 4pm today. I went to use the bathroom at like 7:40 and a huge clot just makes its way out, along with several gushes of blood. It's 8pm here now. Is it possible? I mean, if it's silly, sorry for asking. I don't have much experience yet. The bleeding is still going strong. It was accompanied by a lot of cramping, shakiness, sweat and nausea. Is that actually a thing or am I just coming up with random ideas? Thanks!