Symptoms of pregnancy on BC?

what are the symptoms? is it the normal symptoms a woman would have when she's not on birth control? I'm just panicking right now I take my birth control religiously for 4 months now (I've only missed one pill the first month, and another 3 weeks ago) and I'm only 17 and I have high anxiety so I'm probably just over thinking it! me and my boyfriend are active and we don't use condoms but he pulls out before he even feels close to ejaculating. I am on the 91 day pack only 3 weeks into my pack, before I was on the 21 day. please ease my mind!!!