This leads to situations where people do not have the necessary knowledge to enjoy sex (some even think its a sin) and end up getting pregnant or contracting STD's.
Some tips to stay safe.
1. Use a Condom. Every time.
2. Discuss sexual hygiene with your partner.
3. Wash your sexual organs/intimate areas/penis and vagina/whatever you want to call it, regularly before and after sex.
4. Go to a gynecologist regularly for check ups.
5. If you want to enact something you've seen in a porn movie, discuss it with your partner first.