TFW got pregnant

I'm a TFW as a skilled worker here in Canada, married but separated for 3 years now, I was nominated by the employer for PR and already passed my documents under family. I did not apply for a divorce yet since I'm still waiting for the result of the PR but then I also have a Canadian citizen boyfriend who is also married but separated, we've been together and living in the same house for more than a year now although I did not change my address (until now still using my previous address). I also renewed my work permit for another year when I found out that I'm pregnant. My expected due will be on March 2012 and and my applied work permit will expire Oct 2012. Can I go back to work before my work permit expires even if my maternity leave is not yet over? Can my boyfriend sponsor me to become permanent resident even if we are both technically married? Please help...