is this my boyfriend's baby or my friends baby.

Hi,
Welcome to ehealthforum.
If you had used spermicide (and there was no ejaculation) in your prior intercourse, and if you have had your periods in between two sexual encounters, chances of the one after periods resulting in pregnancy is higher. If you know your LMP (last menstrual period dates), and your current gestational age, count backwards from current gestational age to see if you arrive at your conception date after your LMP or before your LMP. If your due date (completion of 40 weeks of gestation) is known, you can again count back to arrive at your conception date after your LMP or before your LMP. If your periods are regular, and if you take your LMP as Dec 5th, 2011, then your probable conception date would lie between Dec 15th - Dec 24th, 2011, with ovulation occurring around Dec 19th, 2011 (calculation based on menstrual cycle length of 28-30 days). The intercourse closer to your ovulation time would result in pregnancy (after ovulation, egg is alive for next 24-48 hours to be fertilized). You can also request your gynecologist for assistance with getting a dating scan done to look at your probable conception date. The exact results can only be made out after a Paternity test. Visit your doctor/gynecologist for further assistance and clarification.
Take care.