Patented is a compound sanitary napkin with a longitudinal centerline along a longitudinal direction and a transverse centerline along a transverse direction. The napkin comprises a primary absorbent member with a longitudinal length, a transverse width, a thickness, a pair of longitudinal sides and a pair of transverse ends. The absorbent member comprises a fluid-pervious body facing sheet and a fluid-impervious garment facing sheet that is joined to the fluid-pervious body facing sheet. The absorbent member is joined to a base member at the primary absorbent member’s longitudinal direction. Flaps extend laterally outwardly from the longitudinal sides of the base member and contain a proximal edge joined with the base’s longitudinal sides, and a distal edge spaced laterally outward from the proximal edge. The flaps cover a portion of the leg openings of the wearer’s undergarment and are biased toward one transverse end of the base member. Additional flaps are provided along the longitudinal sides of the base member, which is adjacent to the base member’s transverse end. A zone of extensibility comprises a portion of the flaps and is spaced longitudinally away from the flap transverse centerline. The entire length of the flaps’ proximal edges is more than 20% of the primary absorbent member’s length and the zone of extensibility is extensible so that the napkin’s flaps are free from shifting when the primary absorbent member shifts away from the flap.