Does breast tenderness appear right before a missed period if pregnant or before?

Tenderness is common. Breast tenderness is common before, after and during one's period. Breast can also be tender during pregnancy. Tenderness occurs when there is an increase in our female hormones (stress can also be a factor). If you think you may be pregnant, then call your doctor for an evaluation or take pregnancy test from the drug store.
Variable. Usually after a missed period as need sufficiently high estrogen levels to caue the breast growth & tenderness.

Related Questions

Period came twice last mnth and now late this month but cramping and very tender breasts took HPT a few days ago BEFORE missed period and negative.?

Tested too soon. Conception, as defined by the generation of a fertilized ovum, occurs within day or so of the sex. However, it takes about two weeks for the embryo to make enough HCG to produce a positive pregnancy test. Blood test may be done a day after a missed period. Home pregnancy tests should be done 4-5 days after the missed period. Use first morning urine and follow instructions for the test carefully.

Could I be pregnant if both of my tubes are removed? Having all of the symptoms except missed period. Very tender breasts and very irritable.

Low. The chances are low but there is nothing impossible in nature. Get a home pregnancy test. Good luck.
Very unlikely. As long as there is a uterus and ovaries are present, it's technically possible to be pregnant, but without Fallopian tubes it's extremely unlikely. The 'symptoms of pregnancy' are due to hormonal changes. Lots of things can cause hormonal changes besides pregnancy. But if you want to completely rule out pregnancy, a urine test is easy to get, not very expensive, and quite accurate.

Off Yaz (drospirenone and ethinyl estradiol) BC 4 weeks. Had protected sex week after "pill period". Missed period (due today). Tender breasts & lower back. Pregnant/withdrawal from pill?

Could be either. Give it couple of days if no period check a pregnancy test but it may be post pill changes if concerned see your physician.
Likely due to d/c BC. It is not uncommon to have a change in your menstrual cycles - early / late / miss / shorter / longer after stopping oral contraceptives. Your other symptoms can be related as well. However, depending on what u used for protection and how reliably, it would be reasonable to check a urine pregnancy test.