Can anybody tell me what this plant is:

http://sites.google.com/site/iansplants1/

I am not sure whether it's a weed or a plant - it hasn't flowered yet,
and want to pull it up if it's a weed before it flowers/seeds.

I did scatter some Aster seeds in the bed but it doesn't look like the
photos on the packet.

Thanks in advance,

Ian