If you accidentally have misplaced or forgotten your Bitlocker Recovery key, but still have access to the system (with an elevated account), you can retrieve the recovery key quite easily through the command line:
Open an elevated command prompt and type:
manage-bde -protectors -get C:
Replace C: with any drive that has Bitlocker enabled. Note that if it's not the system volume but some other drive that's encrypted, you need to unlock it first before you can retrieve the recovery key.