how do i update the sims 4 on my pc

Open Origin and log in to the account you have the Sims 4 on. If there is an update you will be prompted to install it.

i didnt get the game from origin though, does this make a difference?

@jmw2505, it shouldn't make a difference. 🙂  I bought the base game in a store and updated it through Origin before I downloaded any expansions.  I also have always started my game through Origin.  Just log in to Origin, and in either "My Home" or "My Games" there will be a picture of The Sims 4 in a box .  When you hover your mouse cursor over this, there should be an option to update.  Happy Simming! 🥳