Thanks smv!
Just a note for anyone with a similar case, so you can avoid the stress I experienced.
My common law partner and I applied for PR together and got the visa stamped. It arrived in November. We decided to do our landing on our way back from vacation in Feb because we didn't want to get stuck in case we landed earlier and the PR card took longer to arrive. Panic hit in January, when we remembered all the times cic kept telling us in their emails to update them on any relationship status changes. We were going to get married on this vacation, you see. So, when we land, we won't be common law, we'll be married!
I read on a lot of threads that you must get married after you land to avoid complicating things. But these were all single applicants who got visa stamped and then got married on vacation before they landed on their way back to Canada. The complication was that they would never be able to sponsor their spouse in the future if they did this. But our case was different. We were already a couple as recognized by cic, and had both gone through background checks etc and had got visas stamped. But you never know, what other problems it could cause in the future. Last thing we wanted was a case of misrepresentation on a technical detail like whether we were common law spouses or married spouses. Got no answers on the forum. Called cic and they confirmed that it won't be a problem. Phew! Crisis averted!