Question ladies!!

Kiersten Elise
Hello my name is Kiersten! So basically according to this app I am currently 5w1d pregnant. I took a pg test about four days ago. Which came out negative. My last period was October 25th. I believe to have conceived on the 20th of November. I missed my period as well am having symptoms. Do to conceiving near period how do I go about a pg test? Could you be technically a week pregnant, miss a period, and get a positive??? Thanks for the responses in advance!