Sue, I think you were mis-informed when you purchased this plant.
Alstroemeria pelegrina is one of Chile's endemic Alstroemeria species (please see my entry for A. pelegrina) and is only found in pink (very different pink from your flowers) and, very rarely, in its white form (I have never seen one).
Your A. looks like a hybrid to me. It could have some A. pelegrina genes in it, but is definitely not an A. pelegrina variety/ssp. Please check the shape of the petals of my pictures and the look of their leaves.
ursula
