It is likely to continue to thicken. My beard was very thin and patchy at your age, but for me the mustache matured first. I was in in 40's before my cheeks filled in. Other than the mustache, your beard is much better that what I had at 25. So hopefully yours will mature at an earlier age.
For now, the style you have looks good on you, I would only suggest a little more length, especially on the sides. More length would give it a more fuller look Try setting your trimmer at a longer setting of 1/2 inch (12 mm), then gradually increase the setting even more and give it a try.