Breast lump

Hello. I had a huge mass in my left breast about twobyears ago and it was very swollen and there was blood coming out of it. I did an ultrasound and the doctor said it was intraductual mastitis. I did a mammogram three months after and the lump was gone. I did a follow up ultrasound six months after and they said they saw a small lump. I was recommended to do a core needle biopsy this month. I have not been having any symptoms or see any signs of breast cancer. Do you think i should still go ahead with the biopsy? Has anyone here ever done a biopsy? Isbthere any side effects?