My periods are usually on time, however it came six days late.my first day is usually heavy but it has been light.do you think this shows i'm pregnant?

Not likely: A urine pregnancy test, done correctly, gives a reliable result 3 weeks after sex (3 weeks after when conception might have been), 1 week after missing a period, or 1 week after starting a "weird" period. If done sooner, a positive result is likely real, but a negative result may be due to testing too soon, and thus lead to a repeat test.