Don't know if it's too late or not. You can try, if it doesn't work, nothing lost. Or you can just pick the tiny, unpollinated zucchini and eat them now before they shrivel (what I do if I know the female flowers weren't pollinated).

It's common with hybrid summer squash for there to be a bunch of female blooms before there are any male flowers. That was certainly the case with my zucchini a few weeks ago, but now there are usually male flowers each day and I'm picking a steady stream of zucchini.

I agree with Don that there are often no males for the first bit. You can try hand pollinating, but also if any of your neighbours are growing squash the bees will be bringing in pollen. I can honestly say I have never noticed unpollinated female flowers dropping off my zucchini and I don't worry about it too much.