What Causes Heaviness In Breast With Yellow Fluid Discharge?

i am 28 years old and married also but no having any baby because we don't need for this year but some problem is in my breast that last week my periods are completed but last three days i have some haviness in my breast and when i squeeze it some yellow fluid comes out and i have pain in my brest muscles also. i want to know about my pregnancy is there any other problem?