Its quite normal, unless its blood stained. During pregnancy breast undergoes changes in first pregnancy, where as after 1st pregnancy, the breasts are enlarged and often contain milk for years. In first pregnancy in first trimester( up to 12 wks) Breast enlarges with vascular engorgement. Nipple and areola become more pigmented. Montgomery’s tubercles become prominent. Colostrum can be expressed as early as in 12th week. In second trimester (i.e. from 13 th to 28 wks) breast enlarges even more with veins becoming more prominent . Colostrum becomes thick and yellowish by 16th week .Variable degree of striae may be appear over breasts.