It may help to know that even if you bleed it’s not a period. It’s a withdrawal bleed, meaning a synthetic bleed. While a heavy bleed is a decent indicator you’re not pregnant it doesn’t rule anything out because it is not a genuine period. It is possible to bleed while pregnant, especially since it’s a synthetic bleed.
What determines whether you’re pregnant or not is a pregnancy test but you won’t need to if you use your pill correctly. As long as you use it correctly you won’t get pregnant. The pill doesn’t just suddenly stop working after years of being effective. Its important o know what may affect the efficiency and what to do if things do go sour for whatever reasons. Your pill is your most important thing, a bleed (or lack of) doesn’t really tell you anything. Trust your pills!
However, if you get anxious regularly it’s recommended to use condoms. The stress and regular testing is not worth it just to have sex without them.