It was quite a long time ago (she died 11 years ago), but I still remember a lot about it.
So, yes, it is very hard to spot in the early stages. My Mum had classic early symptoms (feeling full when she hadn't eaten) and was told by her GP that she should go and drink peppermint tea! They eventually worked out what was going on when she started to build up fluid on her lungs. They tested the fluid and it contained cancer cells. By this point it had spread to her lungs, kidneys and all through her abdomen 'like grass seed' in the words of her Oncologist. She had palliative chemo for two years on and off and by then it was in her brain and there was nothing else they could do. She died peacefully in her own home with very little pain, the one saving grace of the whole experience.
Funny you should ask if they keep an eye on me. I'm currently under the care of the genetics clinic at Guys. My Aunt (my Mum's sister) also had ovarian cancer, although they caught it early when they went in to remove an unrelated cyst. So I have been recommended to have an oophorectomy very soon (probably this year). I'm also being tested for BRCA1 and 2, but as breast cancer is unknown in my family they think it's unlikely.
Hopefully your symptoms will turn out to be something else. My Mum never had pain from the ovarian cancer, but from the secondaries, weirdly. I shall cross my fingers for you.
Not sure any of this was massively helpful, sorry.