score:5
1. Give it a tug.
If your bike hasn't docked properly, you should be able to pull it out again. But don't use excessive force. Even if it doesn't come out, it's no guarantee that it's correctly docked.
2. Check your journey history.
Go to the docking station and press the option to print a journey history receipt. You have to insert your bank card so it can identify you, then you will see a list of journeys you made over the last week or so. If your journey is on there, then you're safe (N.B., journeys that last less than 10 mins may not show).