Pregnant?

Darian
So my periods in June and July were about a week apart so I'm pretty sure I was ovulating that whole week in between. I had sex during said week and I'm not sure if it was protected or not. So I had my July period but it was so weird and not normal. It was ALOT lighter than usual and I'm almost a week late for my period this month. I took a test yesterday and it said negative but apperantly the closer you take them to your missed period the less likely they are to read it right? I don't know, I was just hoping someone could ease my mind or something.