Don't panic. Easy to say I know. Before you get on the phone to a locksmith try the following steps.
1. Call a family member or friend who has a spare key.
2. If you are in rented accommodation ask if the landlord has a spare key
3. Have you left a window open? You could try climbing in if it is safe to do so.
4. Call a local mobile locksmith such as BH Locksmiths in Dorset who can get you in.
You are not the first person to lock themselves out and you certainly will not be the last. If you do have to call a locksmith it is a relatively painless experience.
In the future you might want to consider leaving a spare key with a trusted neighbour or local family member, or alternatively you could get a lock safe for the front of your property thought there are of course security risks with this option.
If you would like any advice, do give us a call on 01202 900830