Had one dead bird in front of your house then 3 in your backyard is this mean something bad?

Not all naturally occurring phenomenon can or should be interpreted as an omen.

Birds die in nature all the time, in some cases they encounter an obstacle in their flight path, and run into it to their detriment. Windows on buildings can become much like mirrors depending on the angle of the light, this can confuse a bird into thinking they can fly through the window. The impact can be fatal. If a flock of birds was startled, they would scatter, looking fora way to escape, they may have just been unlucky. As for the one in the front yard, I'd be inclined to think a local cat moved one of the bodies form the back.

I do not think you are in any danger from misfortune.