It is possible, yes. Pulling out before ejaculation can help prevent pregnancy, but it’s risky because guys can’t always tell exactly when they’re going to ejaculate. Also, some guys have a small amount of sperm in their pre cum, which can cause pregnancy too.
Using birth control AND condoms together is the best way to prevent pregnancy AND STIs. You should also use condoms in case there’s sperm in your pre cum or you don’t pull out in time.