Chances of pregnancy?

My boyfriend and I had unprotected sex about 5 or 6 times between last night and this morning.... He withdrew every time but what are the chances of getting pregnant from pre-cum/random floaters left behind from him finishing previously? It's my cycle day 12... I didn't realize it was during my fertile window but my app says it's about 25% chance of pregnancy today so I'm just kinda worried... What should I do?