Boobs?

Why does sore boobs get better during the night.  I am about 4 weeks 5 days and the only symptoms I have are moderate cramps (mostly before bed), and sore boobs mostly during the day, at night they are starting to be less sore!! Is this normal? I freak out everytime I have a cramp or when I don't feel my boobs sore! Please give me your opinions/experiences! Thanks in advance.