Symptoms after falling HCG levels

Hey all! Unfortunately I am experiencing my third miscarriage. It was weird from the start because I had what I thought was a normal period at the beginning of April. However, I am undergoing fertility treatments so I went in for my mid cycle ultrasound. They said I had a huge cyst and it appeared that I already ovulated. Well something just told me to take a test anyways and much to my surprise it was very positive! At that point, I was still spotting brown since my "period" and was having some pelvic pain so I was nervous that it might be ectopic. I went in to see my RE and had an ultrasound that didn't show anything at the time, but my hcg level was only 453. However, two days later it had dropped in half so it was determined I was miscarrying. A week later they checked my HCG level and it was down to 87 (that was on last Thursday). I'm supposed to have a recheck next week to make sure it is still going down. Well yesterday, my breasts started hurting really bad like they did in my last pregnancy. I just can't wrap my head around why they would be hurting so badly with my hcg level being so low. They did not hurt at all when the level was higher. I'm just so confused and wish my body would get it together. Has anyone else experienced new symptoms with failing hcg levels? I understand that you can still have symptoms while miscarrying, but NEW symptoms?!