This is to acknowledge and thank you for your question posted at Avvo.com
In your situation, you will want to wait until you have completed the permanent residence process. This is because after accumulating 180 days of unlawful presence and you step outside the United States you become subject to a three year bar.
Please be advised that my response to your question does not create an attorney-client relationship.
Such a relationship is determined primarily by principles of agency and contract law. The relationship begins when the client acknowledges the lawyer's capacity to act on his or her behalf and the lawyer agrees to act for the benefit and under the control of the client.