What do you think is happening?

Ma

My last period was on 30 of July and it finished on 3rd of July. I had unprotected sex on 11 August but he didn’t cum inside me.

Now I’m 8 days late, eve expected my period to be on 23 of August but I didn’t get it yet.

I did 2 pregnancy test. One on 25 of August and the other on 28 August, both were negative.

What do you think is going on?