been hearing a really weird screaming outside my window..but not directly outside...

[purperose13]

...my window.? its happened more than once, about a year ago when i was reading harry potter seven, i was RIGHT next to my window and i heard this ghastly screech/scream/weird noise, i cant explain it. and another time last year i heard screaming but it sounded like "MOMMY" each time, it was so creepy! and tonight i hear it again, and i don't even know whats going on. its not in my house, and its like REALLY late every time it happens, it just sounds so mournful.. it doesnt sound playful at all. does anyone know what this might be?