What Does Milk Discharge From Breast Indicate?

Hi, I'm 37 and have 3 childred aged 8, 15 and 16. I was sterilised (clamps) 5 years ago. I was wondering if it's possible to fall pregnant as my last 3 or 4 periods have been very light, almost just spotting, just for a day or 2 compared to 5 or 6 day heavy ones. I have also noticed a small amount of colostrum from my nipple.