Can ultrasound and CA bloods miss something? Ovarian symptoms vs.IBS.

Sorry for what may be a confused post. First off I apologise for posting here when I can see many if you are having an extremely difficult time with definite cancer, whereas I am only “worried and wondering”.

I am 46 years old. I have a history of unsuccessful IVF, and I am in early menopause and on HRT.

Back in October I started having a very sudden and very sharp pain in my right lower abdomen, enough to take my breath away and almost double over. It felt like a sharp knife or needle and was gone as quickly as it came but it travelled down my leg and another time it woke me when I was sleeping. I then began to have pelvic pain and lower back ache. 

My GP sent me for a transvaginal ultrasound and all was normal, CA blood tests were normal.i have to admit I was really surprised that the scan was normal - I assumed it was my ovary,   as I had several IVF cycles in my 30’s, during which they were unable to make me ovulate, and the pain afterwards was very similar to this.

The GP said a dipstick urine test showed trace of blood but lab result was clear.  High vaginal swabs showed no infection. Scan of renal system was normal.

i am still having the pain, though it is less sudden, it is more constant and is tender and sort of swollen feeling internally , all on the right hand side of my body/abdomen. It’s mainly stemming from a sharp pinpoint in a specific place in line with my hipbone, but the tender feeling can radiate up to my rib. The pelvic pain comes and goes and I imagine could simply be part of the menopause. intercourse has been incredibly painful for a long time thiugh  this could also be attributed to menopausal symptoms. and have had trace of pink in discharge. Which the doctor is saying could also be menopausal/HRT related . 

 I feel my doctor has lost interest because all the tests were normal. He is saying its probably irritable bowel, and to take over the counter medications, or it may be a pulled muscle and has given me a print out with back exercises to do. 

If it was IBS wouldn’t it be discomfort all over the bowel, rather than it all be on one side and feel like it was emanating from one specific spot? I thought I was a bit old to suddenly develop IBS. My background of IVF, and never having been pregnant, plus being early menopausal and on HRT makes me concerned about risk factors, plus my mum had colon cancer when she was just 3 years older than I am now.

This long long waffle of background info is by way of asking - how reliable is the trans-vag ultrasound? And CA blood tests? i don’t want to obsess over the idea it could be ovarian cancer and become a hypochondriac, but on the other hand I cant help feeling concerned as I don’t feel right and I’m worried about something being missed. 

I plan to now keep a diary of symptoms - pain and any unusual bleeding/discharge etc; but should I be asking for anything else or the scan to be re-done in 6 months or something?? 

Huge apologies for the long post, I am rubbish at explaining things succinctly. 

Thanks in advance to anyone who managed to read it all!!