Constipation a sign of early pregnancy?

Hi everyone, I'm curious if anyone experienced constipation as an early sign of pregnancy? I eat a very very healthy diet and take probiotics, and normally go #2 every day. For the past two weeks I've only been going every 3rd day, and it's really hard to get it out. I also have soreness in the bottom of my breasts. I've increased my water intake, and even tried eating prunes and drinking coffee to help me "go". It's too early to take a pregnancy test, my period isn't due for almost 2 weeks.