Pulling to the right on double action trigger
I have a double action CZ 75 BD. I was doing some dry fire practice today with snap caps and putting a coin (a dollar coin to be specific) on the top sight and practicing trigger pull. I noticed that I could always keep the coin on during the first pull but not the second. the gun fires in double action with snap caps obviously so I don't work on the single action pull much because that's already beautiful with this gun.
Anyways, when I took the coin off and looked down the sights, I noticed that I pulled slightly to the right pulling the trigger. I could take up the slack and get it to half-cock fine, but the extra force to pull the trigger pulled my front sight to the right regardless of how slow I pulled. It wasn't too drastic, my front sight remained mostly in between the back two, but it was a noticeable pull to the left.
How do I fix this? Is this just a strength issue?