I wanted to make a homebrew class and don't have the option to. I wanted to know if it was just me, or it is not implemented? (if so, would it be implemented in the future or no?)

Homebrew subclasses are a feature coming in the future with no ETA given.  Homebrew classes are not planned.  They are certainly possible but require more effort than other features that have been more frequently requested.

Stormknight said it better than I can in another thread.

Quote from Stormknight >>

It's not that homebrew classes are too difficult to code - this makes it sound like the development team are incompetent, which is CLEARLY not the case.

There are several issues, including that it would require a massive amount of time to code homebrew classes in a way that would ensure they are fully compliant with the character builder and have a meaningful and usable interface for creating them. That time is much better used delivering features that a larger number of people want. Additionally, the review and moderation of published homebrew classes would be very time consuming.

ok, thank you very much

I agree, Im wanting to do the spellfire wielder class.  Tried it in the subclass but couldn't get it to work.

I beg to differ on what people want. You go to any homebrew site out there and there are more homebrewed classes than anything else. That should be proof enough that people want to create classes not subclasses. If you're going to offer making a homebrew campaign, then classes should be at the top of that list.