Hello, thanks for using health care magic.
Normal cycle varies from 21 to 35 days and if yours is within that range you do not have to border it is normal. Its abnormal when it lasts more than 35 days or less than 21 days or when it fluctuates abundantly say 21 days in menses 1, 34 days in menses 2 etc.
With a protected intercourse
and with a negative pregnancy
test (assumed it was done after your expected date of menses), it is less likely that you are pregnant.
So what you should do is to retake the pregnancy test in a weeks time and if its negative, you should see your gynecologist for a review and regulation of your cycle if its abnormal.
Best regards and hope this helps you.
Dr Achuo A. M.