Doubts

I had sex with my boyfriend last week and we used a condom (it was my first time as well). We were kind of nervous if the condom worked or not (he even pulled out before cumming) but i took a morning after pill because you never know. I'm nervous because i don't remember when i had my period but i think it was at the end of november and beginning of december and i'm having mild cramps and my breasts are sore, am I having pms and i'm just overreacting?