My breasts changing were what convinced DH that I should take a test. I have massive ones anyway (38DD) but they've kinda...filled out some...and the nipples are ALWAYS hard..and they've gotten darker. Oh yea..and I look like a roadmap cause of all the veins. And they're VERY sensitive. Hopefully I don't go up in size too much! I think mine started to change around 5 weeks!