Friend, if you are waiting for God to tell you what to do with your life, chances are you'll be waiting for a long time. If you're idle and waiting for God to break the silence, well...all I can say is, the book of Proverbs will convict you about that, and you are probably (obviously) missing out on many present opportunities.
I am not saying that God will never tell you what to do. God is more creative than every single human being's imagination put together. He just might. I am just saying it is not the normal thing.
If you tell me that God "called you" to this profession/occupation, I am going to ask you what you mean by that. If you say God placed a burden on your heart, okay, fine. God places a "burden on your heart" for many things. But many believe in the notion that everyone has a calling, and God will tell them what it is, and how to fulfill it. (By the way, I wrote a little book review dealing with the subject of calling and vocation here, so I will try not to repeat what I wrote already.)
Um, here's something from my closet of secrets: God hasn't told me what to do with my life. Am I a weirdo because I haven't (supposedly) found my calling? Is something wrong with me, or, dare I ask, should I even call myself a Christian?
Answers: no, no, and yes.
No doubt, there are many scriptural accounts of people being "called" by God to do great things. What I mean by that is, God actually spoke to them with a real live voice, be it in a dream, or in a vision, or, just in a conversation. What I then ask is, what about all the people who were contemporaries of those aforementioned, but not mentioned in the Bible? They seem to be greater in number than those to whom God gave special revelation/s. Surely there are many godly people not mentioned, and we will never know if God spoke to them in a dramatic way, or even in a not-so-dramatic way. The tendency is to zero in on those portrayed in scripture and say, "Oh, look! God told Abraham where to go. He totally floored Paul when He spoke to him on the road to Damascus, and also guided him through dreams and visions! And look at Jeremiah; God told him his occupation [not a very glamorous one, I dare say]! That means God will speak to me through rainbows and tell me what to do, because it's normal!"
Newsflash: that is not the norm. Chances are very good that you'll never be an Abraham, Paul, Jeremiah, or [throw in someone to whom God spoke in the Bible].
So, my advice to you if you are trying to decide which way to go and what to do: carefully weigh your options with prayer and wise counsel, read Proverbs, and DO IT if wisdom says "yes." God may or may not speak to you, but He is sure to place you where He sees fit, for your good, and for His glory. Just don't sit around.