Major sharp pain in boob

Michelle • 33 year old from Australia , currently pregnant with baby #4 a boy..miss 7 mr 5 miss 1 and prince due 26/01/17
So 22 weeks with #4 my boobs have been killing me this whole pregnancy . Never had sore boobs until after baby was born with my other 3. Today I have the sharpest pain in my left boob . Like someone is stabbing me :( what's going on !!! How do I stop them hurting so much ?