Thanks for the query.
If you had unprotected intercourse
around the time of ovulation there is possibility of pregnancy
Sometimes urine pregnancy test kits may not detect early pregnancy.
But just by symptoms we cannot confirm or rule out the pregnancy.
So you once consult gynecologist get examined and go for ultrasound
By this the possibility of pregnancy can be find out and also the possibility of ovarian cyst
etc can be rule out.
For more details you can ask me through: http://www.healthcaremagic.com/doctors/dr-sree-gouri-sr/63429