If you look at the block history on the blockchain.info homepage you can see the blocks have been a bit erratic the past few hours. Just happens sometimes, the Bitcoin network has a mind of it's own.

It's nothing to worry about, it'll be back to normal v.soon I'm sure.. from my experience there is a block holding it up with a bunch of transactions in it - once that block is finally solved the bottleneck (for want of a better word) will be clear and it'll all flow smoothly again.