Why did i have cramping and sore breasts two weeks before my period was due? my period hasn't arrived yet and it's worse. is this a sign of pregnancy?

Probably not: Your breasts are sensitive to hormone changes which start with ovulation (about 2 weeks before your period) and persist until your next period. Of course if you do conceive this will continue, but that is what home pregnancy tests are for. Cramping can occur with ovulation and then again prior to your period and is also not specific for pregnancy.