Even pre-ejaculat lubricant (pre cum) has enough sperm in it to conceive. I knew a girl who was allergic to latex and had to get ye olde abortion without even having penetrative sex - granted, she was a very fertile, very sexually active and something of a bullshit artist at times - but still - there's a reason why "unplanned pregnancies" still happen in this day and age...even if it is because fools have unprotected casual sex, but that's a whole other conversation).
It depends on a lot of factors.
Let's hope you just got the clap, as opposed to getting her knocked up.