Do you have to have breast tenderness to be pregnant?
Not necessarily, every woman and every pregnancy are different.
My breasts were extremely sore with my first, before I even missed a period, but I had hardly any discomfort the second time around
PMS can cause breast tenderness as can peri-menopause and menopause. Taking birth control pills can also give you breast tenderness and believe it or not in some older women drinking too much caffeine. Before I went for my yearly mammogram I was told not to drink any caffeine 24 hours before getting the test. Some women (from 20 up) can form cluster lumps or small non-cancerous lumps and by drinking too much caffeine this can raise them enough in the x-ray for the technician to become suspicious and worry yourself to death. Nix the caffeine when going for a mammogram! Also some medications can cause breast tenderness so when taking any medication (especially any medications with hormones such as birth control or Hormone Replacement) expect sore breasts.
In some women this can be extremely uncomfortable so wear an old bra to bed to support your breasts during this time and you're sure to have a good nights sleep.