Cornell University is a real good source for gardening information. Okay, I will often stop at the U of Idaho site when looking for an answer on potatoes but, considering my location, try not to make this too embarrassing for me, okay
[url=https://www.gardening.cornell.edu/homegardening/scenec6be.html]Cornell:[/url] "Days to emergence: 14 to 28 - Sprouts from seed potatoes should emerge in 2 to 4 weeks depending on soil temperature."
Looks like you are right in the middle of that time range (depending on soil temperature). How well sprouted was the seed when you planted? You will see the soil lift and dark green, rolled leaves beginning to emerge.
Cornell also says, "Do not plant seed potatoes until soil reaches 40 F." Yeah, well I think it certainly should be above 40F in my garden but not much
I also think it had better be my potato planting day tomorrow.
I decided the seed potatoes should find themselves in a warm spot for a few days since they will be taking up their garden location soon. Over the last 5 days and at only 51F in a basement "cold" room, they've been growin' just fine, thank you!
At least I got them out of their paper sacks and into a box.
Wishing you the Best of Luck with Your potatoes!
We are each other's harvest; we are each other's business; we are each other's magnitude and bond. ~ Gwendolyn Brooks