The unknown pink flowering bulb

A short while ago I spotted this bulb had produced a long stem and buds on it. It was in rather sorry looking pot which I think I must have planted a year ago, as it also had produced an off shoot, which hadn't grown very much. When I saw the flower buds getting bigger on its stem last week I brought the pot indoors. Within two days  the first flower began to unfurl.

Today I suddenly decided I should record it as the first flower to unfurl was already beginning to crinkle up. Unfortunately by the time I got around to getting my camera out it was nearly dusk. I need to get my tripod out in future when conditions are like this.

If anyone knows the name of the plant I'd be interested to find it out.