4 days late

So my last period was in August on the 9th, it lasted for about 2 1/2 days, and on the second day I had protected sex but the condom broke and he says he pulled out in time. I decided since my period stopped completely after the second day that I should take a test and so I took one on August 14th, and another August 20th, both came back negative and I used them exactly how the paper said. My period was supposed to come September 6th, and I’ll be 4 days late starting tomorrow. Is there any chance I could be pregnant or is it because of depo? Not that it matters that much because you can get pregnant at any time but I’ve been with the same guy for 5 years now and since before I was on depo (I’m an idiot don’t judge me) we’ve always had unprotected sex and used the pull out method. I started having unprotected sex at 12 and now I’m 17 and I’ve never been pregnant before, but I have had a late period that was almost a month late before and I wasn’t on birth control. I started depo last year and stopped about 9 months in and decided to take my last shot so I don’t have a huge chance of getting pregnant. The only symptoms I’ve been experiencing are cramps and bloating, even back pain; so should I test again or should I assume it’s the depo shot?

I forgot to add that I took my last depo shot on August 12th, three days after my period started and it stopped altogether after that. I stopped taking depo around Jan-feb and had my first period off of it in May.