I have done two minutes of Dr Google on this topic as I clearly have too much time on my hands.
I found one article referring to someone with no medical qualifications who had suggested peas were the enemy. I found another site saying peas were a good source of manganese that helps with estrogen production.
There is no "avoid" list apart from cigarettes, excessive boozing and drugs. Just eat a sensible balanced diet with a range of fruit and veg.
I suspect you would have to eat a hell of a lot of peas to get any contraceptive effect from them. And I dread to think what other effects doing that would give you.
Actually I have too much time on my hands because I have googled Sarah Dobbyns fertility diet and it doesn't sound like much of a laugh at all. By month three you've got no meat, no dairy, no peas, no alcohol, no caffeinated beverages, no sugar etc and you then have to cut down on eggs and fruit juices.
I wouldn't have the energy to have a shag on that diet personally. And that would NOT help fertility. This woman thinks her magic diet will allow you to delay childbearing until whenever you like.She even suggests it will help people have children in their 50s. Which is virtually impossible.
I'm sure having a healthy diet is important for your fertility (and general health) but please don't believe any bollocks you read on the internet.