Hi, You have done the right thing by taking Postinor as even the precum contains sperms. The Postinor drug itself does not cause change in the colour of the urine. The fingering might have caused small abrasion on the vaginal mucosa resulting in mild bleeding. This can explain the red colour of the urine you saw. If you have not had enough intake of water the urine becomes concentrated and it appears yellowish red. Both these are temporary causes. If the urine colour remains so on the third day also, despite drinking enough water, then you need to see your doctor. To avoid such unnecessary stress I advise you to consult your doctor and start regular contraception like hormonal contraception or have an intrauterine device fitted as they are more effective than Postinor in preventing pregnancy. It is wise to use barrier contraception like Condom to protect yourself from sexually transmitted diseases. I hope I have answered to your satisfaction. If you have any further queries do contact me through healthcare magic