When sizing a chain I use the big/big method: Wrap the chain around the two biggest sprockets, figure the shortest place you could join the chain and add 1 inch (2 links) of chain to that. That yields the shortest chain that you can safely use with that gearing combination. Surprisingly, the length of the derailleur cage doesn't seem to matter because, when you're in the big/big, the derailleur cage is pulled nearly horizontal so the lower chain run is almost straight.

It sounds to me like you initially forgot to add the two additional links and then adjusted by adding more links than you really needed to add. I doubt it will matter because, with only one chainring, your chain wrap needs are relatively modest. I'm thinking you're good if you ever decide to switch to a 36 tooth rear cog.