You might be anticipating recoil.
Here's a little exercise to try (get some snaps caps, and this involves dry firing).
Take your pistol and establish a correct, two-hand hold. Find an aiming point and concentrate on your front sight while you aim. While doing this, gently squeeze the trigger all the way to the rear. You should only be using the front pad of your trigger finger.
If you do this right, the hammer will drop and surprise you a little bit. You will also notice that the front sight will not have moved.
Once you are comfortable with this, you need to do the same thing at the range. Do not worry about speed. Concentrate on getting an even trigger squeeze all the way to the rear while focusing on that front sight. The gun should surprise you every time it goes off.
If you practice this, you will get tighter groups. If you are getting really tight groups, and they are in the same place every single time, you can then worry about maybe adjusting your sights to the point of aim. Be aware that different types of ammo can create slightly different strike points on the target.
I hope this helps you at least a little bit.