GENERALLY, precum only contains sperm if you have not used the bathroom and washed that area of your body since the last time you ejaculated. Precum itself contains no sperm; however, if you ejaculate and do not use the bathroom, there could still be live sperm in the tubes; and if you haven't washed since, there's a small chance there could be live sperm on your skin. HOWEVER, it is definitely possible that you can get someone pregnant that way, so especially if you don't remember if you used the bathroom and washed since, better safe than sorry - pregnancy
In regards to the under-16 thing in the first response: In the United States, age of sexual consent differs state by state. For instance, in Kentucky, 16 is the age of consent as long as the other party is not older than 18 (i.e. a 16-year-old and an 18-year-old can have sex and no statutory rape charges are possible). Also in the United States if *both* parties are underage I don't believe statutory rape is a possible charge unless there is more than four years' age difference (so the girl would have had to be ten years old).
Second answer person: Yes, you could be pregnant. It's highly unlikely, but it's possible. Also, most home pregnancy tests
can be used 2 weeks after the first day of the missed period, and there are many available now that can be used as early as the first day of the missed period.
I can't really say anything about your age without being a hypocrite, as I got pregnant with my first son at the age of 15, but just think about that for a minute...