Laura,

I don't know anything about growing watermelon as I just bought a sugar baby seedling from the farmer's market. However, I think you should have seen something by now. Do you have anymore seeds in which to try again?

That's what I was afraid of. I think if these seeds are a bust I'd be better getting transplants from the greenhouse down the street - especially since there's such a limited growing window for watermelons here - but didn't want to plant new transplants only to have the old ones sprout up as well.
~ Laura

Here in Oklahoma we planted Black Diamond watermelon. We did three mounds of them. Only one came up with around 5 seedlings. I planted so much more. When I felt enough time had passed and weather permitted, I planted a second round out of the seeds I had left. All have sprouted and are growing like weeds now. Try again with what you have.

20 yrs gardening in a difficult zone 5a, i consider myself an 'insurance' gardener...
For summer and winter squash, melons, pumpkins...., i have 12 well spaced mounds...
5 seeds in each hill last weekend...5 more will go in this weekend...and a seed starting tray i started a couple weeks ago.
They tray is doing well and still small. -these crops do not like transplanting at all but i do it close to planting time, soil warm, temps. 4-6 inches is perfect.
Really not much trouble but i avoid having to purchase with so many seeds anyway by sharing and exchanges and seed saving last years crop seeds.
Too much moisture and rain this time of year for me, we often get seed rot...they turn to mush if i look for them after no germination...
A good year all comes up fine...
With multiple seeds in a hill, i can then select the strongest plants and cull the others...
After up and strong and surviving cutworms and such maladies...3-4 plants per hill.

Easter seems like premature planting for such a warm season crop as watermelon. I doubt very much that soil temperatures were warm enough to promote germination.