The first thing to do is not worry about it ? dwelling on the matter will only make things worse.
?Trigger freeze? is often a nervous condition that stems from a shooter?s anxiety over a target, or simply by trying too hard.
However it can also be caused by an ill-fitting gun ? usually one that?s too long in the stock.
My advice would be to have the trigger pulls checked by a gunsmith just to make sure they haven?t gone heavy; if that?s the case get them lightened off and see if that helps.
Second, if you?ve got a friend with a gun slightly shorter in the stock ask if you can try it over two or three clay shoots ? it might make a difference.
For some shooters trigger freeze is a real problem but by the sounds of it you are experiencing a very mild form of the condition (as do most folk from time to time) and by ignoring it chances are it will disappear.