Extened Long LD

Lately of a night i have been having extremely long lucid dreams, i'm not saying that it is bad just is kind of annoying me a little now after about a week of it. Such as today i just had a sleep in front of the tv and had a really long lucid dream but it was only about 20 minutes of my time but i felt i had the need to wake up.
would anyone have any kind of explination for this, i have been doing tests at school lately and been under a little stress, but other then that everything else is fine.
Any suggestions?

Cheers