A septum for a port is provided, the septum having a top wall and a side wall. The side wall can include a pressure-activated valve element for regulating the flow of fluid across the valve. The curvature of the side wall and the geometry of the sidewall and the housing can be tailored to bias the valve element to open at different pressures during infusion and aspiration. The side wall can also include an extended portion that can function as a suture wing for securing the port within a port pocket.