Have had it twice before CD.
Once successfully - 1st attempt - age 36. Had treatment in Bangkok while living in Vietnam. Wasn't really working so not an issue.
Second time unsuccessfully - age 42 - overweight too. Had treatment here in Budapest - def wasn't as user friendly as Bangkok. Much more stressful.
I am note sure about chances CD - it is all very much dependent on why you haven't conceived since etc. In our case my DH is both impotent and infertile so no chance of a happy accident.
All I can say is it isn't as bad as some media articles would have you believe.
And 15% chance is 15% more than you have any other month.