Hi I am 19 nearly 20 years old and my boobs have been sore for past a week now, 10 days ish. I have the nexplanon contraceptaion implant however it is almost time to get a new one (hitting my three year mark) in february. At first it was both of my boobs, nipple and all that was sore. Now it's just the underboob/side boob that feels sore. There's no way that I'm pregnant being on nexplanon (even took a test to make sure). Im wondering if its possible that they're growing?? They havent grown in years though so thats whats confusing me. Also I havent had a period in over a year (which is normal) due to my nexplanon implant. My boobs used to get sore before periods for about a day, but that is no longer since i don't get my period anymore. Im wondering if its possible side effect from nexplanon? However, i havent had this side effect before and I'm close to the end of my 3 year mark where I'm no longer getting side effects from it, like i did in my first year with it. Any advice would be very enlightening!!