I get sore achy breasts for two weeks every month.
I have never been pregnant.
Short story:
Once someone ovulates, they produce progesterone. Progesterone causes symptoms such as tender breasts, bloating, a rise in basal body temperatures, etc - preparing the body for the possibility of a fertilized egg to implant. If an egg is fertilized and implants, then the body starts producing HCG. HCG causes the same symptoms as Progesterone.
The end.
If it's still 'early' then the symptoms are from Progesterone and not pregnancy-related.
If you're actually having pregnancy related symptoms (symptoms caused by HCG and not Progesterone) then you should be able to turn an HPT positive.
GL!