It indicates "어(eo)쩜(jjeom)" which is a contraction of "어쩌면(maybe)".
Also it is used as an interjection when somebody has got a good impression of something or surprised or could be embarrassed, and mostly it's used by women in casual conversations.
macam mana - 어쩜 좋아. = 怎么办啊。
oh~~my~~god - 어쩜, 세상에나 = 我的天啊。
As for "I am shy", it simply means "저는 부끄러움(= 수줍음)을 잘타요" or
"저는 수줍움이 많아요"