My Last Menstrual Period Was November 26 I Had Sexual

My last Menstrual period was November 26 I had sexual intercourse with my bf on December 5 on December 17 I had sex with someone else with protection but I'm scared it might of popped or anything, I'm 7 weeks and a few days and today I'll find out how far along I really am I just have a concern on which person I actually conceived with