SCAP....SNAP!

Let's say you show up for 8AM Mass and Father Uriel is not there. Instead, the Deacon, Tom or I read the Sunday Celebration in the Absence of a priest. You receive the Eucharist, but when it's over you realize that you are not inconvenienced by having to drive to Anna to attend 10AM Mass.

Can you receive Holy Communion again?

 Father Z. Explains:

The law is clear. The faithful who are properly disposed can received Holy Communion once a day, and then once more in the context of Holy Mass.  To receive more frequently is an abuse.

  
The 1983 Code of Canon Law says:

Can. 917 – Qui sanctissimam Eucharistiam iam recepit, potest eam iterum eadem die suscipere solummodo intra eucharisticam celebrationem cui participat, salvo praescripto Can. 921, § 2.
…
Someone who has already received the Most Holy Eucharist can receive it again (iterum) on the same day only within the Eucharistic celebration [i.e. Mass] in which the person participates, with due regard for the prescription of can. 921 § 2.

And… can. 921 § 2 says that if a person is in danger of death, he may receive Communion even it is not in the context of Mass.  That is Viaticum.
That iterum does not mean “again and again”, but merely “again, one more time”.