I dont know what to think about this... My girlfriend has had one of her areolas change to a dark color while the other one has stayed the same color. She has been constipated, had an increase in appetite, I have notinced that her pulse has quickened, just by holding her had I can feel her pulse. The same breast that she has has the change in areola color is extremely tender. She appears to be putting on weight, although she is ver small, I can tell. Yes, we have had sex without contraceptives. She is about ready for her period and she thinks that this is common for her, I have never noticed this before. She is unusually clingy and wants to hold hands and hug more than usual. What do you think about the one areola changing color but not the other? I havent said anything to her but I think she is pregnant.