I just finished my period 4 days ago. Why are my areola's bigger and veiny? My period was lighter and shorter (2-4 days) and spotty. Help!?!

Possible. If your period was abnormal and you have been having unprotected intercourse, pregnancy is a possibility. To know for sure, do a pregnancy test and repeat it in 3-5 days if it is negative. If it is still negative, pregnancy is not the cause of your breast changes and it is unlikely that breast cancer would cause bilateral changes. Hope this helps.