I am sorry that this has been such a stressful journey for you. It is enough to have gone through a miscarriage and to have difficulty conceiving without the guessing game about ovulation. It definitely seems that you should get a new doctor and what about considering a RE? I also cannot recommend the ovacue system enough. It is expensive but it is much easier to tell when and if you ovulate. The ovacue does not use urine tests, which frankly were terrible for me and some months did not catch my ovulation at all. Instead, it reads your saliva every am and then gives you a 7 day warning about approaching fertility and actually predicts your ovulation. There also is an additional vaginal sensor which actually confirms that ovulation occurred. Again, this system is expensive but it is heck of a lot cheaper than other fertility treatments - at least that is how I looked at it.
best of luck and tons of SSBD to you.
I know, it's all so confusing! I don't rely soley on the OPK tests, I use them along with checking my cervix & CM and that gives me a pretty good idea of when I'm Oing. I don't think the OPK test are as accurate because they show any LH levels and sometimes you could not be checking at the peak or have had too much to drink which can dilute the urine. I'm no expert of course but just from my experience, I don't really trust them completely.
As far as getting pg after MC, I'm not sure. I've heard of women getting another BFP right after a MC and others not. I'm sure it does take it's toll. I had to switch docs too and so far I'm happy with them. Maybe that will help you to understand things better. You've definately got to feel confident about your doc! Good luck and keep us posted. SSBD to you!