I was in my room,on the second story watching tv with the lights on

there i my bed lined up with the wall,at the corner,and a window across from it

the window was on my left and i was laying in my bed

a green beam of light hit my roof through the window

the area was about fist sized,and it was a complete beam,not fading to the outside

there was more then 1 beam of light

i saw nothing and no one outside

it happened twice

at night

Ps the is a tree straight outside,so it mustv came from an angle

any ideas on what it could have been?could it have been a laser light refracted somehow to make it look like 2 beams of light?and expanded to make it look bigger?hmm I have a stop/slow sign that construction workers use,with the slow sign poitning out,right next to where it hit,maybe it bent the light?no idea...please help im freakin out