When should i test again?

Ive tested several times including on Nov 10, day of AF being due. Still no sign of AF and white milky egg white mucus in excess. Im trying to save money and reduce the amount of tests i buy. When should i test again with a frer? Im thinking monday the 12th but would that be a wasted test aka too soon? I OV on the 26th according to OPKs.