Hi peaboe girl,
I would'nt worry about it being an ill fated omen or anything like that.
To set your mind at rest, it's probably nothing more than a flock of North American robins that have flocked together in a period of harsh weather with the soul aim of finding food and surviving. I've even noticed birds of different species will sometimes flock together in the winter, in the wood's near my home, I've seen large flocks of Chaffinches, blue tits, long tailed tit's, great tit's all converge on an area looking for seeds etc. Good Luck Tbird+