Door-to-door gynecologist rings the bell and says, "At your cervix!"

Selected pages from the 32 page book, Pardon My SEX, Doctor by Vic Herman. There's no publication date, but it appears to be either the late 50s or early 60s. 

During a career as a cartoonist, illustrator, author, teacher and painter, Vic Herman created many advertising characters such as "Elsie the Cow" for the Borden Company, "Johnny" for Philip Morris, "Winnie the Wac" for the United States Navy, and "Sad Shad" for Johnson & Johnson. He was the author of over 52 books and had cartoons and magazines in many national magazines. He was also a teacher for the Boards of Education in Los Angeles and San Diego. Source: "Who's Who in American Art", 1993-1994, p. 519