Here's how you can check
http://www.quiltingboard.com/t-89997-1.htm
Once you figure it out, use tape to mark your machine. If you usually use the same weight fabric and thread, it should not change. May need to recheck if you switch to a heavier fabric like thick flannel.
It's really worth the small amount of time it takes to figure out where it is on your machine. Blocks will come together much more easily.