Steer clear of pregnancy

My boyfriend and I just recently started having sex, and we had a moment where we got freaked out that I may have been pregnant. We then realize we couldn't have been pregnant because We've been really careful. We really don't want a baby right now, so I've been using glow to figure out all the safe stuff. I just wanted to know how affective glow was with not conceiving? Or if there's any other way to give me a safer place of mind.