They become sore due to the changes going on within your breast - the production of milk.
Yes , some women have experienced sensitive nipples from the day after conception onwards. Of course it varies from person to person as some do not experience sensitivity until the later stages of the pregnancy but it is still normal to experience it early on
Nipples will darken during pregnancy.
Yes, during the later part of pregnancy they will swell and become slightly red.
Yes, my breast were extremely sensitive during the first twelve weeks.
Yes; it is common to have sore nipples during the first trimester of your pregnancy.
No the nipples do not change colors.
yes, breast changes significantly! They become bigger, firmer and the circles around nipples become much darker. At the end of pregnancy they sometimes start leaking colostrum.
That is perfectly normal.
They grow into proper baby suckling nozzles. Until the first pregnancy, thick, prominant nipples would just be nuisance.
Yes they usually gets darker during pregnancy and breastfeeding.