It's not happened again

Katharine
I have been so positive this month. I have woke up to the usual monthly cramping so know my period has arrived. So so upset. My fiancé will be too. 
I just wish I knew what we were doing wrong.
We are due to marry in September and I really wanted to be pregnant by then.
If it doesn't happen next month then we will have to stop trying for a few months due to our honeymoon as I won't be able to fly past a certain stage if I did fall pregnant, so that means another delay!!! 
I hate this x