Why won't the 2nd branch form on my phal?

[nidiasophia]

HI,

I have a phalaenopsis orchid that I bought at the supermarket (I believe a doritaenopsis hybrid or something like that). It has one spike with one branch (all the flowers are opened), and from one of the nodes below the last branch, I see the tip of what looks like another branch that wants to come out.

However, it has been like this for a month now. The other branch is just peeking out from the node and is afraid to come out.

Is there something I am doing wrong? How can I make the branch grow? When I acquired the plant, I was only watering it, not feeding it. I just started feeding last week.

Any tips?