I have had the same dream a few times now. I have dreamt that I lost a boxing match. I have a fight coming up does my dream mean anything to that?

It depends on what type of fight.
If you have a boxing fight coming up, then it could be a dream preparing you if you do lose and helping you experience what may happen.
If you have a fight coming up with someone who you don't like and want to hurt, the dream may be telling you to stop before you get hurt or that it's not worth all the energy if you're not going to get anything out of it in the end.
Hope I helped :)

It might also mean that your sub conscious is showing that you have a fear of losing that fight.