My blueberry bush had a lot of white flowers on it, but now they've all but a few disappeared. Upon closer examination, it looks as though they were picked off or dropped (although I don't see any flower on the ground around my bush). Could they have dropped from a brief cold snap we recently had? Or do birds eat the flowers, too? Also, could a fungal disease made the bush drop their flowers?
Depending on the stage of bud and flowering that the plant was in, the temperature drop may have affected your plant.
Here are some links that will help you.