Awesomecatholic is saying what I’ve always been taught though. I have been in the situation before of not getting to the front of the confession line before the priest had to leave for Mass, and sometimes he says he will come back after Mass and those of us still in line can go to confession then, but never has a priest said that we can all go to Communion because we’re going to confess after Mass anyway. Many of us do go to Communion because we were only planning to confess venial sins and believe ourselves to be in the state of grace.
In my case I go to confession usually twice a month because it’s required for private devotional practice, and almost never do I have a sin to confess that I’d consider possibly grave matter. The one time I did have such a sin and couldn’t confess till after Mass, I refrained from Communion.
There is nothing to feel sorry about in my case. I don’t go around questioning the priests all the time, but when I’ve been taught a particular thing and have tried to follow it for years then I’m not going to do something different based on a priest suddenly saying something out of the blue. Priests occasionally come up with real lulus, and the more so if the priest seems inexperienced or has a reputation for bending the rules. If I really felt I missed out by not receiving that Communion, I would simply attend another Mass later or the next day and receive at that one.