Breast Pain spreading through right breast

I am a 27 year old mother of two. I pumped/BF both boys for 3 months each. I got thrush on my nipples when my youngest was 3 months old. I finally got that cleared up. My youngest is now almost 2 years old and my breasts are really hurting. The pain starting under my arm and has moved its way around my right breast. The nipple is really sensitve too. I still have milky discharge sometimes (mostly when my son cries) but not a whole lot. I have lumpy breasts anyways and they are a DD so I can't tell if there is a new lump or not but the pain gets pretty bad. My question is could this be breast cancer or just an infection. I don't have a Dr right now but I am worried because my stepmom is dying of breastcancer and I have lost 3 other family members to breast,cervical and ovarian cancer over the last 4 years. Any advice, information or experiences would be appreciated.

MY BREAST PAIN IS IN ONE AREA ABOVE MY R 3RD RIB IN FRONTAIL IT HAS BEEN THERE FOR ABOUT 4 YEARS OFF AND ON, BUT WHAT IS WORRING ME IT HAS GOTTEN WORSE WHERE IT WILL LAST FOR DAYS AND MY RIGHT SHOULDER HAS BEEN PAINFUL FOR ABOUT ALMOST 2 MONTH. I AM AFRAID BECAUSE MY MOM DIED OFF BREAST CANCER. I AM NOT GOOD ABOUT GOING TO THE DOCTORS EVEN THOUGH I WORK IN THE MEDICAL FIELD, I AM 42 AND SCARED I WONT TELL ANYBODY BECAUSE I DONT WANT THEM TO WORRY, I WIL JUST MAKE A COMMENT OF TWO REGARDING HOW I FEEL. WHY YOU ASK MY KIDS LOST THERE FATHER AT 43, I LOVE MY HUSBAND SO MUCH AND CHILDREN I DONT WANT THEM TO GO THREW ALL THE THINGS YOU MAY HAVE TO DO IF YOU HAVE CANCER ESPECIALLY BECAUSE I DONT DRIVE;. MY HUSBAND CAN NOT TAKE TIME OFF WORD FOR ME, HE WORKS SO HARD HE NEEDS TO TAKE CARE OF HIMSELF, HE WANTS TO HAVE GASTRIC BYPASS SO HE CAN FEEL BETTER AND THAT MEANS MORE TO ME THEN MY ACHES AND PAINS;. I LOVE THEM SO MUCH I DONT EVEN KNOW WHY I WROTE MAYBE TO JUST GET THAT OFF MY CHEST SORRY FOR THE POOR SPELLING ETC THIS KEYBOARD IS NOT GOOD THANKS FOR LISTENING D