Whether you "should" or not depends on what you want. I don't know if you will lose your progress on reading, though memorizing is something like its own muscle which needs to be used and strengthened. Memorizing doesn't just exist in a vacuum though, it is linked to as many things as you understand about music, but all the same you want to practice putting it all together in a way that helps you to play pieces by memory.
If reading is your goal, it's a similar thing in that it's a kind muscle that you want to use and practice. I memorize all of my pieces, but I am also regularly sightreading now, too, as a kind of "separate" muscle group (though that doesn't exist in a vacuum, either). Ideally, aside from my main repertoire, I would work my memorization muscle with a kind of program of very short and relatively easy pieces (for me) each day. I'm not that organized yet.