Possible pregnancy? Scare.

I did my first-time sex on July 31 (Friday)
I also did it Monday-Wednesday.
My expected period was on Aug 4th (Tuesday)
My last period was July 4th.
My days between periods are usually 31-36, and I am about 7 days late.
I took 2 pregnancy tests yesterday night and today but both are NEGATIVE. I believe that it may be too early if I was pregnant.

All of the sex happened with a condom, I do not want kids or birth control (but might have to after this). I checked every condom after use for tears and rips using water to see if it would leak. None. We didn’t have any slip-offs.
He did pull out after he finished every time. But I believed that the rubber band at the base did roll up and could maybe have leaked pre cum.
I searched it up that some pre-ejaculate could possibly contain sperm. And we used TONS of astroglide lube and Google have said that it may could have slowed down sperm or even kill it because of how acidic and thick it is.

All I am worried about is pre-ejaculate. But why would my period be so late if we did everything right?
I thought it could maybe be because it was my first time and it was a sudden rise in activity. I’m trying to not add any stress to further delay my period, but I can’t help it.

I know I should wait 14-21 days after sex to take another pregnancy test but I do want to know opinions from
others. I know I’m not alone. Please listen to my story.