Well, it didn't actually help us get pregnant but I got my cycles back at 16.5m after cutting out night feeds at 14m and slowly cutting back day feeds as well.
You *might* find regular, boob-free nights does the trick. It's also possible you're one of those women that can't get cycles back till they wean completely - you won't konw till you start cutting back. I guess you have 3 choices: do nothing and see; cut back slowly and see; or wean completely and see.
But good luck! I know that feeling - it really hit me when DS was about 15 months old.