How did you find out you had cancer??

Hi, this is going to be a bit of an epic post so apologies in advance. In November 2019 went to my GP with left sided hip pain. (I was in a job where I was on my feet for 12 hours a day) Saw a locum GP who examined me more than my normal GP, found I was tender to his touch on the right side of my abdomen so sent me for blood tests and ultrasound scan. Found a cyst on the ultrasound so saw the Gynaecological team and as the cyst was 6cm, they decided to get it removed. Blood tests came back all clear, even my Ca125 was within normal range.  Had cyst removed on January 18th 2020 along with my fallopian tubes as they said could lead to cancer so best get them out, as I'm nearly 62, did tell her I wouldn't be needing them again! :)  On 28th January had a telephone call from my Gynae consultant to tell me I had Stage 3b ovarian cancer. Bit of a rollercoaster after that, had major surgery on 27th February, full hysterectomy, started 6 sessions of chemotherapy, had Carboplatin and am now in remission but am on Lynparza tablets for up to next 2 years, unless recurrence in that time.  The reason for this post is I want to ask how anyone's cancer was detected, having regular scans and blood tests but as the tests in November didn't show anything,  I'm now terrified that it'll return and the scans or blood tests won't pick it up until it's too late. Know ovarian cancer is known as the 'silent killer' as really difficult to detect but apart from nausea for several months prior to seeing the locum GP, which my normal doctor just gave me tablets for, then had absolutely no symptoms at all. I've got coeliac disease so my doctor thought I wasnt adhering to my gluten free diet, but  I'm really strict about anything I eat.  Sorry for the long ramble but be interested to see what other people think?? Thanks xx