From F1 to undocumented to greencard

I am a British citizen who came to US for college on 1999. During that time I enter US as a F1 student. On 2003 since I lost the finical support from my family, I dropped off from school. The student visa expired few years later after that. In 2006, I was caught commiting a felony of writing bad checks on 2004. I was on probation for 4 years. During that time my attorney told me that immigration does not have my record or else I have been deportation back to my own country already. And now on 2013, I m planning to marry my boyfriend who has been had a crush on me for more then ten years since college. He is a US citizen. My question is, was my felony commited before would be a consideration for the immigration officer to reject my greencard application even they realize our marriage is a real one. Would deportation happen to me if they refuse my greencard application? Thanks for answering.

Honestly, your case is a little complicated and it is best to consult an immigration attorney.