A little help here

So I’m 19 And this is a little embarrassing but I just started taking birth control and I just lost my virginity not to long ago sex was never really an open subject in my house so there are still a lot of things I’m confused on I take a birth control shot and with that the birth control last for 3 months and the shot takes away my period so I no longer have one as long as I’m on the shot recently me and my long time boyfriend had sex for the first time because I’m on birth control it was unprotected so if start my period on birth control does that mean I’m pregnant ??