I think the earliest I have tasted a sour is at about 4 months. Usually they have some slight sourness to them, but not much. Lacto and Pedio don't really have a large enough population initially to have much impact on the flavor, taking up to a year to get to their maximum population. Is it lactic acid, or acetic acid (vinegar) that you are tasting?
Some acetic acid is good if not a dominant flavor. The Brett and the lactic acid will help balance the beer, but you need to leave it for at least a year for them to fully develop.