Is it too late to start with another type of pumpkin from seed?
One month ago you said you had 120 days left until average first frost. That suggests you are now down to 90 days left. That's really not enough time, even for baby pumpkins, unless you get really lucky and have a late frost. (The frost dates you see are just averages and in these global warming times, it isn't unusual for frost to come later than average.)
For next year, you need to figure out what you are doing wrong. The problem isn't the seeds, it's how you are treating them. There's generally only two reasons seeds fail to sprout: too much water or too little water. If seeds once they have come out of dormancy and are getting ready to sprout are allowed to dry out, they die. But since we all love to feel like we are being good seed moms, way more seeds die from over watering than under. If they stay too wet, they rot out and die. This problem is worse if the soil is cold (or even cool in the case of pumpkins).
Part of your problem apparently is that you planted ALL your seeds, so when they failed to germinate, you didn't have any left to try again? Seed packets are usually at least 15, maybe 30 seeds. Unless you have a farm, you have no reason in the world to plant 15 pumpkin seeds. Pumpkin plants are gigantic. Plant a few seeds. They should sprout in anywhere from 5 - 10 days. If they haven't shown up in 10 days, try to dig some up to see what happened. If you didn't water enough, the soil will be dry and the seeds will still be sitting there, dry and shrivelled. If you over-watered, the soil will be very moist and the seeds will be mushy and rotten, unless they have totally rotted out and disappeared by the time you check. Then plant again!