I have this issue again this month. We were on vacation, and intercourse was about 2-3am. I woke up and took my temp at 7am. So, charting intercourse for the next day am doesn't seem accurate, but technically neither does charting for that day pm. Right now I have it charted for that day pm.
I would probably just chart it as "Yes", if you're using FF. I had a couple nights like that, counted it as the night of the 13th instead of the morning of the 14th, and left a note in the notes section.
I always wonder what to do with that too. If its after 12am I usually chart it as the next day am. Since it is the next day i guess? I wonder what the right thing is to do go by your sleep or time of day?