I am starting a clothing line so should i trademark my name before mentiong it?

My clothing line has been under devolpement for three years but the name was created by my older brother and years down the line i gained a love for clothing and since late 2006/early 2007 i've been working on my brand. I am going this week to draw up my logo with a well know graphic design company and i really wanna just scream out my clothing name but i know for legal reasons i shouldn't but not all clothing companies are trademarked so i am really asking am i at risk of getting my name taken if i mention it or should i hold off??????? I seen on youtube this kid has started a record company with the same name as my clothing line although i don't know him so i feel i should let everyone know i was here first and stake some type of claim????? any help or advice is welcomed thank you btw which company should i register with for my trademark???? and i already searched the upsto trademark files and no one has the name of my line so i feel i am good to go.