Thanks for your query.
You could not be pregnant from the encounters you have described.
This is because you have clearly stated that you are a virgin and no vaginal penetrative sexual intercourse has taken place.
Also, you are on birth control.
The missed period could be due to the concurrent medications, and the stress
wait for a week, and if you fail to menstruate, consult your gynecologist to rule out conditions like polycystic ovaries