So sorry OP. It's utterly shit.
I too have unexplained infertility and the months just passed, clinging onto that bit of hope.
I did however get a head start, it was 8 month I went to GP and totally lied and said it had been a yearand they done the basic tests, sperm, ovulation etc. When there was nothing wrong, they referred us to the fertility clinic.
Whilst waiting in the NHS referral process (approx 4/5month from GP to hospital) I had tests done privately. I had my tube test done and had a few months of Clomid.
Once i had my appointment with the Gynecology at the hospital, she didn't need to re-do the tube test or waste time on Clomid. By this time is was nearly 2 years, She referred me straight away for IVF.
Once they do that, things go like a flash. Had my first IVF in May and now 20 weeks pregnant.
Get the ball rolling, get private tests done whilst waiting for NHS. Don't put off having treatment in hope you might fall naturally. You may fall pregnant while waiting for IVF. Give yourself the best chance.
Hope it goes all weel for you 