Honesty

Ok so I'm 26 and have 4 kids. My oldest is 12 and youngest is 4. The older 3 are girls. I struggled hard growing up with no father(not even a name) and a drug addict and alcoholic for a mother. The only person I had to turn to was my grandmother who has now passed. Being a teen mom was hard and not too many go through what I've went through during it but what kills me most is that there's teens out there just having sex like jack rabbits and not even being honest to their parents about it. I'd want my kids to talk to me about it so I can give them advice and get them on birth control so they don't have to worry about getting pregnant. I've talked to my oldest about it already. I know the struggles girls about parents not understanding and being overprotective. I get it but do you understand why? Your babies unintentionally having babies because of a feeling or pure pressure or because you want to fit in. I just don't understand why they feel like they should lie.