Help with Glow Nurture?

Ashley
Can someone tell me how to change the dates to correlate with how far along I am? I don't know yet at this point how far along I am but I'm sure it's more than 3W1D like the app says I am. According to what I've found online, an at home pregnancy test won't pick up the pregnancy hormone that early and I've gotten 3 BFP results. 
TIA!
-Ashley