When i started my portfolio thread i forgotten to add a Subject..
So i edited it and changed it to 93Matt93's Portfolio but the thread name is still no subject.
Anyone knows?

its because when you edit you edit the subject of the post, not the thread

Yep.

You need to open a new one, and ask for a thread deletion (If this is possible).

I know

I am going to link the first post of a thread to it's subject name.
So, if you edit your first post, the subject of the thread itself will change.

I forgot to do that when I made the forum.