The fee chart at https://bitcoinfees.21.co/ is a best guess but when the network is very busy can take longer. If you are in a hurry always use a higher fee. If you use a good wallet like Electrum you can mark the transaction as replaceable; if it does not confirm quickly with default fee you can click on the transaction in the wallet and bump the fee up. The blockchain.info wallet is probably the worst on the market for estimating the proper fee to use. We get more complaints on late transactions from users of that wallet than any other. Relax, your transaction will confirm just not as fast as you hoped.