Forecast Consumption Logic

I have read a variety of the posts on here and don't think I saw a clear answer on forecast consumption logic…..

I am currently testing to understand the consumption logic before we launch forecasting.  I have created a weekly forecast of 6 pcs/wk for 6 months and then entered sales orders for 5 weeks that are both under and over that weekly qty.  It seems like the logic is to ONLY consume forecast within that week and not backward or forward consume forecast - Is that correct?    Is this a setting we can modify to set the # of weeks/days forward and backward to consume?  Our customer orders are not as consistent as a weekly forecast would assume and this would cause us the need to constantly reforecast or clear individual weeks each week forecast wasn’t matched or potentially overplan our demand when forecasts are not met, which is why consumption logic is often an MRP setting.