Are all of the eggs fat and round at one end and noticeably narrower and pointy at the other? Do you have other poultry that could be sharing the nest? The reason I ask is that they may not all be Guinea eggs. Guinea Hens will frequently share nests with each other but they will also share nests with other poultry/birds too, like Wild Turkeys. Post a pic of the eggs if you can.
As Barbara stated, Guinea Hens can have big cupped wattles too. Males can have small flat wattles (some breeders focus on specifically breeding for that to avoid winter frostbite issues), and both sexes can have one of each... so wattle size/shape is never an accurate way to determine sex. Nor is their behavior. I have Hens that act tough/aggressive and charge/chase other Guineas the same way my males do... but they buck-wheat and or lay eggs so I know they are Hens.
If you really want to know how many Hens you have... coop them all up, catch one at a time and separate them into a cage or crate away from the rest of the birds. Wait (out of sight) for it to either buck-wheat or not. Hens typically start buck-wheating right away. You can band their legs with colored zip ties so you can identify your Hens if you have all birds of one color/variety.
Casque size (bony growth on top of the head) varies in my flocks, depending on genetics and age. Not all my birds are from the same gene pool... there is no size and shape standard that applies to all of my birds, male or female. Typically the males will have a larger casque than a Hen of the same age, but an older Hen will have a larger casque than the younger males in my flocks. I wouldn't recommend using casque size as an accurate indication of sex either, unless you know the exact ages and lineage of each of the birds you're comparing.