Protected sex but no period?

So the last few months my period has been getting later and later. In September I was supposed to get it around the 17th but didn't get it until the 24th. In October I don't remember exactly when I got it but it must have been after the 24th because I remember freaking out that it was late. So this month I assumed it would come around the 24th but its December 1st and still nothing. Me and my boyfriend only had sex 3 times in November. We used a condom each time and he has never finished inside me because even though he uses a condom we want to be extra safe. My breast hurt and are swollen, i'm gassy, my period may or may not be late, i'm having the clear white discharge i normally get. So do you think It's possible that I could be pregnant or is my period just taking its time getting here? I keep telling myself I'm not because we used protection and didn't finish but I know precum can still get you pregnant but again we used a condom. What do you think?