I had sex 5 days to my period and i did not know if am going to miss my period because i did not use any pill....can i still use it or wait till i see if i miss my period or not?

Maybe. Call Dr. now: Otherwise, a urine pregnancy test gives a reliable result by 3 weeks after sex (3 weeks after when conception might have occurred), or 1 week after missing a regular 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. If a woman gets her normal regular period, then she is not pregnant.