Something very strange happened today. blockchain.info let me send 1.48 BTC when I only had 0.6. I had a incoming transaction of 1 BTC. For some reason it made the sending transaction twice (received and sent BTC in the same block) and it is displayed as unconfirmed and my balance is negative.
screenshot:

Can I remove the unconfirmed transaction? Why did it send twice?
exact same thing happened to me, i suggest you to import your private keys to mycelium for now and look how much balance is available for spending.