Different priests have said different things about this.
Once, that was about two years ago, I was very late for a weekly mass, I came shortly before communion, and the priest said at weekday masses it was different and I could still take communion.
Another priest last year said the same thing.
Then, this summer, I went to communion even though I had been late and after mass talked to the priest, and he said that the mass was a whole, the liturgy of the word and the liturgy of the Eucharist together, and out of respect it would have been better not to come to communion (but since I hadn’t known or hadnt been sure, it wasn’t a sin that I did come). Now I was confused and asked still another priest and that one said it was ok to come if I was here for the part that had to do with communion.
So I had all these different viewpoints on my mind when today I came to mass late (not purposely, of course). I came after the first reading, during the responsatory psalm. So I wasn’t sure if I could go to communion or not, but I really felt the desire to go. So I went up to the priest as the last person and asked him. He seemed to waver a bit at first but then said, yes, I could, but to say a prayer afterward (I think he meant after mass). Which I did and was happy.
Now, is there any official guideline about this? Or is it a matter of interpretation? I wonder what other people have heard or read about this matter. Thanks