I'm so scared please help..?

I came off the pill in june and had a natural period in July 7th, I should have had a period start of august. Only i've had was August 9th. we did use a condom but have bn feeling really tired. I'm hoping my period is about to start. Test is negative.. I'm all over the place as i'm worried about my delayed period but that could be because irregular periods after the pill. Im stressing out and can't think about anything else.. When should I start to test ?? esp if periods are not regular???