Trying to get pregnant

I'm very nervous that I won't be able to get pregnant... My fiancé and I have had unprotected sex for a while now and nothing has happened... We weren't necessarily trying to conceive before, but now we are.  I spoke to my doctor and she said I probably just got lucky and wasn't ovulating at during prior intercourse which would explain why conception wasn't achieved. I have been taking daily ovulation tests for a few weeks and have had no luck yet. If anyone has any tips, advice, or comments, I'd love to hear it!!