Need help

I started birthcontrol August 3rd(I stopped taking them for various reasons, mainly because I didn't like how they made me feel)Okay so August 9th I had sex with my boyfriend and he was freaking out telling me I'm pregnant because of the side effects from the birthcontrol so I made a doctors appointment for August 22nd and I took a test which came back negative. I stopped taking my pills that same day. My period for September never came but I didn't pay any attention to it so I sex September 14 . I have been off my pills for a month now. Was the test wrong or was it too early to test ? Or is my late period because I stopped taking my pills ? I'm so confused and need some help or a little advice. I do plan on taking another test .