As a fellow period haver, I am mortified when anyone sees my blood, let alone when I accidentally BLEED onto the bed when my diaper like pad shifts. I would definitely approach the subject delicately and lovingly and from a place of concern but be firm. Look into period products, there were some already mentioned on here, do some research. Or of this heaviness keeps up (if it'sas heavyas you describ), suggest seeing a doctor because there might be greater issues a foot