If i have sex on day 14 of my period cycle, will i get pregnant?

You may: Sexual intercourse at midcycle, if ovulating, is the best time to conceive. Ovulation may occur, on average from day 12 to 17 of a 28 day cycle. Getting pregnant at age 17 is a poor life choice decision, that has a less than desirable health and socioeconomic outcome for mother and baby. If sexually active, use contraception. You may be lucky and not get pregnant this time.

It depends...: If your periods are regular then you can expect to ovulate ~14 days back from the last day of your period... So you'd ovulate on day 14 if your periods are 28 days apart, day 16 if 30 days, and so on. You are going to be most fertile around the day you ovulate. Btw, you can buy an ovulation predictor kit from a pharmacy to find out when ovulation occurs.

Possibly: If your periods come about every 4 weeks then day 14 would be your fertile time. Women have up to 15-20% chance of getting pregnant in any cycle though the chance can be lower depending on the person's situation.