Two weeks ago, my girlfriend came over and she wanted to have sex but I did not have a condom at hand. So we decided to use the pull out method. While I was pulling out I came on her vagina by mistake and a little bit of cum got inside( it was clearly visible, it did not go far). I used a finger to scoop it out. Not to take any chances , I went to the nearest gas station and bought some spermicidal condoms. I put one on and had another sexual intercourse, hoping that the spermicide would kill any small quantity that was left inside.It's been two weeks and my girlfriend is not experiencing any symptoms of pregnancy but we are both really nervous. What are our chances of being pregnant. What can I do?