Can someone help?

I had sex on the Jan 26 and my period was suppose to be one the 5th of feb as the app says. The past two months my period changed dates but seems to be more is so accurate the past year or so. It’s the 16 and I still haven’t got any thing. My last period was Jan 5th. The thing is I have taken 8 pregnancy test and all come out negative. Am I testing too early or something? Someone help me Please.