Thank you for your query.
From your query it looks like you have not reached your menarche yet, but it is quite possible although a very rare coincidence where in you ovulate in the same cycle have sex around the same time and a conception can take place without even having a first period. After 21 to 25 days after the sexual exposure you can opt for a home pregnancy test.
Hope that answers your query. Have a good day.
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.