Most women are prepared and thoughtful about risk of STDs and risk of pregnancy in their sexual encounters. And don't just think 'what are the chances,' although it's good to know some facts about that! And when the partners have been together and faithful and have a plan for when to begin unprotected sex for the reason of planning pregnancy, it's a completely different situation than if a woman had an unplanned encounter with a new partner. If you were to go to your gyno and ask what tests or treatments you might need to consider after unprotected sex, possible treatments could include antibiotics for prophylaxis against sexually transmitted infections, hepatitis vaccination, tetanus prophylaxis, medications to protect against herpes, HIV and urinary tract infections, as well as a prevention of pregnancy. Pregnancy encounters are somewhere between 8-25% risk, STD acquisition depends on the virus or bacteria, and your susceptibility, so harder to estimate. For the prevention of pregnancy that you can take for up to 5 days after sex you can use Ella. For an over the counter morning after pill you can take Plan B. And for those without active infections currently you can consider getting the copper IUD as an emergency contraceptive. There are many sites for resources on the internet that discuss emergency contraception. Whether you need to go to the extent of vaccinations and antibiotics depends upon you and your individual risk status and risk tolerance, so it has to be a discussion between you and your gyno.