Hello there.
I can understand your concern.
There is a saying which goes like "There are no virgins in a maternity ward"
So going by the literal meaning, its absolutely not possible to be
pregnant without having sex.
Missed periods can be due to a lot of conditions only one of which is pregnancy.
Get yourself checked out by a gynecologist in person for further evaluation and management.
Best regards.
Dr. Anil kumar jain.
Bangalore.