I've been here and speak from experience. First of all, you cannot get pregnant if you don't ovulate, as ovulation is the release of an egg from your ovaries. Second, there is only ONE thing that can definitely confirm ovulation and that is a blood test, done around 7 days before your period is due, to check your progesterone levels. Anything over 30 indicates ovulation has occurred.
When I came off the pill, AF didn't return, and I went to the GP. Blood tests confirmed that I wasn't ovulating, so I was given progesterone to induce bleeds and referred to a fertility specialist. After all the usual tests and scans, I was prescribed clomid: a drug used to provoke your body into ovulating. Whilst going through all of this, I spent an absolute fortune on ovulation kits and thermometers etc. to try and check/track my ovulation. I would be lulled into a false sense of security time and again with the OPKs, as I would get LH surges (and the tests would therefore read positive), but bloods would confirm that the surge hadn't actually been strong enough to stimulate ovulation. I would also get EWCM (fertile cervical mucus) at 'the right' time, but again my progesterone levels were ridiculously low and I had no natural periods, so my cycles simply hadn't returned. Tracking my BBT wasn't successful as my nights were quite disturbed and I've never been much of a morning person, so taking it at the same time every day was too much for me too.
To cut a long story short, we are now blessed with a 6 week old DS, who took 15 months to conceive, from coming off the pill to falling pregnant. During that time, I only ovulated 3 times, so it was third time lucky (and the highest dose of clomid) for us.
It was simple to tell that there was something not right with me, as I had no periods, but if you are not sure whether or not you are ovulating, don't rely on OPKs, BBT, EWCM or anything other than a blood test from your GP to tell you. Good luck and I hope you have some answers soon x x