Frustrated!!

My fiance and I have been ttc since December/January and it just won't happen!! We are both healthy and fertile as far as we know, I have been pregnant twice before but did not carry to full term either time. I don't know when I ovulate and I've heard too many people say opks and temping isn't an accurate way to detect ovulation and the only way to know truely is via ultrasound. So, we have been baby dancing every other day from CD 7 when my period ends until I see AF again so that whenever I do ovulate there's always the chance of conception. But even then I'm seeing a negative test every month, Am I really having this many annovulatory cycles?? Who knew planning to get pregnant was going to be this hard!