Am I pregnant?

I may just be paranoid, as I often am, so I decided to ask some other people. I’m 15, started the Depo-Provera shot a little over a month ago. I got the injection during the last few days of my period, and had sex with my boyfriend about 2 days later. I did research of course, and read over and over again that it works right away if you get it while on your period. We’ve had sex multiple time since then. Now, my current period is roughly 7 days late. A few days ago I had some lower abdominal pain that did NOT feel like period cramps, but it’s passed now. I’ve also had period cramps for the whole time I was supposed to be bleeding, but no blood whatsoever, just some discharge (which did look normal to me). I’ve also been very gassy the last few days. I know Depo particularly f**** with your hormones and therefore periods, but has anybody else had it mess up their FIRST period after the shot? I found out about ectopic pregnancies with Depo, and while I know it’s incredibly rare, I’m now sorta freaking out. Im also 90% sure I have endometriosis but haven’t been tested because my parents don’t believe me and refuse to get me tested for it. I know Depo works slightly differently with endo so I’m wondering if anybody else here has experience with that too? Any advice would be helpful, as my parents don’t know I’ve had sex yet, and telling them I’m now pregnant would most likely result in a “prolonged trip” to some other family members house until I graduate.