Losing my virginity

I'm newly 16 and my boyfriend (17) of 5 months and I are getting to a point where we are moving closer and closer to sex. So close that I'm pretty sure the next time we're together that it's going to happen. I'm on birth control but have really strong hormones, so idk if it'll work. We're planning on doubling up with a condom, but is there anything else we can do to prevent pregnancy even more? Also, is the morning after pill available to minors for purchase?