Ask the Resident (Sex) Advisor
The Resident Sex Advisor answers sex-related questions from college students
If it has been less than 72 hours since this incident, there's still time for your girlfriend to take the "morning after" pill, which will prevent a pregnancy from occurring. Contact your local Planned Parenthood or health clinic to get more information. If it's too late for the morning after method, you're just going to have to keep your fingers crossed till she's due for her next period.
There can be thousands of sperm in a drop of semen, and there is also sperm in pre-cum, the fluid that leaks out of your cock when you first get turned on. Sperm are small, resilient, and they're fast swimmers. So never, ever go spelunking in your woman's cave of love without a raincoat.
Sex Toys 101
Resident Sex Advisor Questions from Women
Resident Sex Advisor Questions from Men