Sore breasts but positive test?

Krysten
I read that if your breasts are sore a week before your period is due you most likely aren't pregnant, that they won't hurt until the day of your missed period or conception at the earliest. Well I don't know if I've conceived but my breasts have been sore since 6dpo. Please tell me this article is non sense and what dpo did your breasts get sore before your bfp?