Help!! Stressing out!

I know I’ve posted here before with the same issue but now I have an update. My past post basically stated that I started taking my birth control exactly two weeks after the end of my last period. After one week, I started having sex and I let my boyfriend cum inside me. I wasn’t ovulating that week either nor was I close to my period date. However, my period is now late by 9 days. At having my period late by 2 days, I took a pregnancy test (one that can tell before your period if you are pregnant) and it came back negative. However, I read that you are suppose to take it in the morning and I took mine in the evening. Now I talked to a doctor but they said that periods could change their start date when you start taking pills in the middle of your cycle like I did but it could also mean that I’m pregnant and when I said I took a test and it was negative but I took it in the evening, they said then there’s a slight possibility it’s a false negative. What’s your guys opinion?? What should I do?? Any tips??