Miscarriage or very heavy period??

Hi everyone, this is my first post and I’m freaking out.

My ‘period’ started last night. I was woken this morning by excruciating stomach pain/cramps, these were so painful that when I got out of bed I was doubled over and couldn’t walk properly.

I went to the bathroom (full pad overnight which doesn’t normally happen on the first day) I sat there for a little bit in pain then I felt something move inside me and then fall out.

When I was done I checked the toilet and I see this... now my pain has mainly gone.

If this a period clot or a miscarriage?!

M