Unfortunately you don't meet the requirements to be considered under the common-law class. As to whether you'd be able to apply as conjugal or not, I'll leave that to other members that may have a better understanding.
Source:
http://www.cic.gc.ca/english/information/applications/guides/5289ETOC.asp
*edit*
Just a thought - if you are serious about applying for the common-law stream - this is a great time to start getting together the evidence that they'll be looking for when you apply - for example, setting up a joint bank account if you don't already have one and making sure that you're listed on each others insurance policies etc if you aren't already. Good luck!