Name that Flower

I stepped in to cover for Mr P at Mass this morning and also ended up helping with teas and coffees.
I did some more cooking and gardening in the afternoon (as well as lots of relaxing reading). One of the advantages of a new garden is being surprised (usually pleasantly) by new plants and flowers coming into bloom. These delicate flowers have just appeared but I’ve no idea what they are. Answers on a postcard please.