5days left until next month, still no sign of period. brief mild aches left ovary today & headaches. when to test for pregnancy? chances of pregnancy?

After missing period: A urine pregnancy test done correctly will give a reliable result 3 weeks after sex (or when conception might have happened) or 1 week after missing a period. If done sooner, a positive result is likely real, but a negative result may be due to testing too soon, and therefore lead to a repeat test. If a woman has her normal regular period, then she is not pregnant, and the test is not needed yet.