According to the Southern California Center for Reproductive Medicine, a woman in her 20s has a 20-25% chance of conceiving naturally per menstrual cycle. In her early 30s, the chance of pregnancy is 15% per cycle. After 35, the odds of pregnancy without medical intervention are at 10%. After 40, that number falls to 5%, and women over 45 have a 1% chance of conception. 
Taken from this article :
https://www.cnn.com/2014/01/22/living/pregnancy-big-lie-tanya-selvaratnam-books/index.html?c=&page=0                  
Re: **ignore** didn't know this article was posted already. More details to the 20% chance each cycle
Me (30) DH (31) Married 5/13, TTC since 2/13
BFP # 3, EDD 2/21/15 * please be our rainbow*BFP #1 Blighted Ovum resulting in D&C on 11/1/13
BFP #2 Ectopic Pg, lap surgery on 3/12/14, R tube removed