Sexual relations which occur between adults and teenagers under 18 are left in a legal gray area: laws against corruption of minors as well as estupro laws can be applied to such acts, at the discretion of the prosecution.
Typically, Mexican states have a "primary" age of consent (which may be as low as 12), and sexual conduct with persons below that age is always illegal.
Sexuality Information and Education Council of the United States (SIECUS). 3.“Emancipation of Minors – Laws | LII / Legal Information Institute.” Cornell University Law School.
Pharmacist Provision of Emergency Contraception to Women Without a Doctor’s Prescription.
Different ages may apply if one partner is in a position of power or authority over the other, such as a teacher, manager, coach, parent or stepparent.
For example, in Indiana the age of consent is 16 but it is illegal for a person over 18 to have sex with anyone under 18 if they work at their school, are their parent or a stepparent, or are a person recruiting them to join the military.
Historically, the age of consent applied to male-female relationships; same-sex relationships were often illegal regardless of the ages of participants.
Keep in mind that the laws may be different depending on the type of sexual behavior—vaginal, anal or oral—and the gender of your partner. Title X clinics offer many services, including prescriptions for the Pill, pregnancy option counseling, and testing for pregnancy and sexually transmitted diseases, including HIV. These clinics charge on a sliding-scale fee basis, and you can pay in cash. If you go to a Title X clinic, your appointment will be completely confidential, including your billing and your records. Title X clinics provide sexual and reproductive health care to the public (girls, boys, teens and adults).