Lots of times, pumpkins put on male flowers first, just to get the bees' attention. Do you have female flowers, too?
Whether or not it is too late depends upon your first frost date and the variety of pumpkin. My first frost date is September 22, and I am growing a smallish medium pumpkin known as Sugar Pie. It just began producing two weeks ago, and I think I will squeak under the wire with ripe fruits.
I'm not too worried. Last year I started them too early and had harvested almost all of them by the beginning of September. I want to try to get closer to Halloween this year.
By the way, I ate some corn today, and I didn't like it. I mean, it was good, but it was more starchy than sweet. Reminded me of the old Golden Bantam (I think) that I used to grow years and years ago. I'm gonna try again tomorrow and see whether I waited too long to pick it or whether it's just not a tasty variety