Tips I can share about this:::
If you can, use first mornings urine. Like as soon as you get up when it's most concentrated.
Wait the appropriate amount of time. 2.5 weeks after the sex you think you may have gotten pregnant from is long enough to get a result, OR the first day you miss your period, OR if you use an early detection test, they work 4 days before your period is due.
On toilet, hold test in flow.
Read within 10 minutes.
Do not let it sit as it can develop an evaporation line which looks like a positive but is NOT.