I'm 7days late on my period and my breast are very sore...could i be pregnant or can it just be my hormones because last month i was 5days late and did get my period?

Could be either.: Reasons for missed / late period include: an anovulatory cycle in which no egg is released, marked v or ^ in weight; eating disorder; Over-exercising (endurance athletics), stress, travel, significant illnesses, oral contraceptives & other meds, Illegal drug use, breast feeding, hormone imbalances and medical problems (i.e., PCOS). Pregnancy is #1 reason. Take a home pregnancy test to know.

Blood test for HCG: If you had sex since your last period, you may wish to take a blood test for HCG level to settle the issue. Have a healthy diet, exercise 30 minutes/day, drink plenty of water, have safe sex, no tobacco alcohol weed or street drugs. For nutrition: http://www.choosemyplate.gov/. Get HPV vaccine. Wish you good health!