Can I safely plane glued boards that were joined on end grain?

I'm a woodworking newbie trying to make an end grain cutting board, and I've just glued two boards together along their faces. Initially, I had a 20" long piece, but I had to crosscut it because of a knot. Now, the pieces I created are too short to run through the planer individually for final thickness. I'm worried about the glue joint between the end grain—will it be okay to plane it like this, or is there a risk of the pieces exploding in the planer? Am I in trouble? Thanks for any help!