Scared about results

Hello. I will try to keep this as short as possible without letting out the details. I am 2.5 years out from surgery and radiation. I have been taking Tamoxifen since completing radiation. I just had my every 6 month check up which includes a diagnostic mammo and MRI. I was considered high risk bc I had one margin that wasn't clean. Prior to having BC, I had breast implants. After radiation, I slowly started to get capsular contraction in the radiated breast. This August 2019, my cosmetic surgeon operated and removed the excess scar tissue, replaced the implant and was able to take more tissue from the tumor bed that was left unclean but was radiated with boosts. The pathology was negative on all the tissue.My BC was in the lower portion of my breast. Yesterday, I went for my mammo, mri and exam. After my mammo, I was called back to have a second picture. The radiologist saw a dense area at the top of my left breast. I was then sent for an unscheduled Ultrasound. I met with my BS before my MRI and she said the U/S was negative but she will wait for the MRI results to make a full determination. My exam was negative for lumps. I am so scared waiting for my results of the MRI. Should I not be worried since the U/S was negative? My BS says it could be scar tissue but my PS didnt touch that area, only the bottom half of my breast.