I thought I would post as I'm about to go through some investigations that others may find helpful. When searching on here, often you don't get the end result, and it's like reading a book to find the end page missing 
I'm 45 and started the mini pill in Feb due to heavy and painful periods. I was previous had the mirena coil but continued to spot give or take a few days so after 2 years I had it removed.
The painful periods remained, accompanied with epigastric pain
and pain when opening bowels like someone had a knitting needle and stabbing me up the lady parts and bum. Moving forward, I started the mini pill in Feb 2024, constantly spotting for 8 weeks again so came off. The spotting continued (withdrawal bleed) for 5 weeks until I then had a full period. Once the period finished, all was very good as everything stopped. 14 days later, bang in the middle, I started spotting again, which got heavier (dark blood) and this would then lighten throughout the day and had then repeated for almost a week (it will be a week Thursday since the spotting started)
I called my doctors yesterday and had a telephone consultation with a wonderful ANP who is sending me for an urgent scan and to have bloods including Ca-125. As I'm an ANP myself, I picked up the forms and got another ANP to take my bloods and then drop these to the pathology department with the hospital (not many perks being a nurse but this definitely one of them )
So the waiting game begins