Unwanted pregnancy related. Pregnancy?

On 1st Jan of this month, Me and my gf were making love. She was not wearing her panties and I was in my briefs. I know this was risky behaviour but we got intimate. After sometime I noticed a sticky wet patch outside my underwear(probably because of my pre - cum) while her vagina was wet too. I am now confused whether my so called pre-cum fluid exchanged with her wet fluid can cause pregnancy. I neither penetrated nor ejaculate inside her, there was only exchange of wet fluid which I am unsure was pre-cum. She took one unwanted 72 pill (emergency contraceptive pill) after 4 hours, her last period came on 13th of last month and she is expecting her periods on either 9-10th. We were expecting the bleeding after pill, but it did not come, today is 5th day after taking the pill. What could be the possible reason for the same and the chances of her pregnancy?