Hi, I'm new to this forum, but not new to Guineas (or other forums). Figured I'd add in my 2 cents on this topic...
If you are letting your Guineas out to free range every morning, chances are that they may have already started laying outside somewhere, which is what most Guineas (if given the choice) will prefer. Not many people I know that own Guineas are lucky enough to have their Guinea Hens lay eggs in the coop or covered run. Mine do, but I keep my main breeding flock in until they lay their eggs, then I let them out to free range in the after noons. Have you looked around your property (and even the neighbor's property!) for outdoor nests, or even randomly dropped eggs?
Hopefully you have already switched your flock over to a good quality Layer feed as their main diet, and that they have free choice access to oyster shell? If not, that may help with egg production. Also leafy greens like fresh spinach and romaine lettuce help add some extra vitamins and minerals, if your birds are not out free ranging for their own greens yet. Also if their coop or run does not get much light, that may be what's delaying their egg laying too...
I'm in Northern California, and have been collecting and incubating eggs from 2 separate flocks since the first week in January. Lucky for me, cold rainy weather does not slow my Hens down much. As of this evening, my hatch count is up to 82 keets so far with another 16 eggs pipping in the hatcher, and I have 3 full incubators humming away
Hope you get some eggs soon!