Ginkgo biloba is probably the most popular herb today. Boosting your odds of conception is probably not a good use for it.
Many herbs come from low-growing plants, but ginkgo bilobo is a tree that bears exceptionally stinky fruit. The tree is ancient, with some in Asia estimated to be thousands of years old. It truly is like the dinosaur of trees. Interestingly, the tree is either male or female, with only the female bearing fruit.
The extract has been studied in memory loss, Alzheimer's disease, and dementia, and it shows some efficacy, probably due to its potent antioxidant properties. It is most definitively an anticoagulant, increasing your risk of bleeding. For a normal, younger person, that's probably not a concern, but for someone who takes aspirin or other medications that can increase bleeding, the combination could be dangerous or even deadly.
For conception, there is not much evidence to support its use. It actually may, because of its anticoagulant properties, prevent embryo implantation in the uterus. While it may be true that it increases blood flow to reproductive organs, the possibility that it would impair implantation makes it questionable to use when trying to conceive.
In a study conducted at the Loma Linda University School of Medicine, researchers exposed hamster eggs to gingko biloba, and the eggs became more difficult or even impossible to fertilize. If you actually took gingko biloba, how much would reach your eggs? Nobody knows, but I'd say just knowing this would make me pretty wary of taking gingko biloba if I were trying to conceive.
There are other way to increase blood flow to the reproductive organs, if that's why you are taking ginkgo. For example, femoral massage will do the trick as can pelvic massage. Moderate exercise increases blood flow in general, while strenuous exercise will decrease blood flow to your abdominal organs. And acupuncture can also improve blood flow, plus it is so very relaxing! L-arginine could do the job, too.