The wonky cycles are a normal part of perimenopause. I started with that when I was around 37-38 and was miserable for 10 years, when my periods stopped at age 48. My already horrible PMS (physical symptoms) got worse. I did have a breast cyst when I was around 33, but after a mammo and an aspiration, nothing came of it and it's never returned.
Glad to be done with all of that! The worst thing was, my periods stopped for 11 months, twice! I thought I was done and then it started up again. Hot flashes were nothing compared to the PMS that i suffered with almost 2 weeks out of every month.
2015 Trek Silque SSL
Specialized Oura
2011 Guru Praemio
Specialized Oura
2017 Specialized Ariel Sport