Hi and thank you so much for this query. I can understand the stress and anxiety this has caused to you. let us ove on and address the worries to have definite answers All unprotected sex can lead to pregnancy. Because you had one and your period hasn t returned, please consider doing a pregnancy test to understand what the most likely cause is.It is a simple test that can be done in the comfort of your room and requires just urine for testing. Pregnancy is the most common reason why a girl of your age would miss her menses. Please, consider adopting and using a contraceptive measure. Also, consistent and correct use of condos in addition to preventing against unwanted/unplanned pregnancy would help keep you safe from infections. I wish you well and hope this addresses your query fully. Thanks Dr. Ditah, MD