Breaking Bread in Acts 20

Acts 20:7   On the first day of the week, when we were gathered together to break bread, Paul talked with them, intending to depart on the next day, and he prolonged his speech until midnight.

How many doctrines hang on this verse? I can think of several (okay, maybe not on this verse alone, but much literature cites this verse when speaking of these doctrines):

(1) Sunday as the day of meeting.

(2) Lord’s Supper every Sunday.

(3) Lord’s Supper only on Sunday.

I’ll continue asking the question I’ve asked in the last two posts: how do we know this is the Lord’s Supper, over against, for example, Acts 2:46? That seems like a pretty important thing to me, especially considering the weight we’ve hung on this one verse. There’s got to be some people that read this blog that believe this verse refers to the Lord’s Supper and teaches the things I list above. Will no one step forward?