Sore breasts

Last night my breast started hurting like crazy!! I mean they're out of a bra I ain't moving or anything and they are aching like it feels like someone is sitting a brick on them and squishing them.. I had this when I got pregnant with my son, around 4 weeks I started noticing it! I found out by test at 6 weeks I was pregnant... I'm trying to conceive and my period is due in a week! I'm hoping that this is a good sign!! Any opinions?!