I just wont stop spitting

Im starting to worry myself. Did the mouthwash rinse this morning, swishing gently, let it leave my mouth gently still. Then, because for some damn reason since the extraction there's been a bucket of phlegm sitting at the back of my throat, I spat.

Huge chunk of blood came out, I worry it's a clot. I got nauseous and had to sit down after. Not sure if the pain I've been feeling since I woke up is the typical pain or something more serious (Day 3ish all 4 teeth btw)

I'm trying my best to simply swallow everything in my throat but it hardly does anything. It doesn't help my worry that I can't see the upper extraction sites, only the lower. But after the blood spit, the only place I could see blood was at the back of my throat

Did blood somehow just build in the back? or do you think I disloged a clot... how immediate would the pain of that be?