unidentified

I don't know what this plant is, in the flower bed. It went unnoticed among the grape hyacinths because it has such a similar growing habit, but then I noticed the hyacinths were beginning to fade and not this one; it stood out strong. Also, it doesn't have grass-looking foliage, but low-growing spread of round leaves. Is it a weed with a pretty flower? or a plant okay to encourage. Anyway, I like the way it looks.