having sex a few before u are pose to get your period

i have a quick question i had sex with my boyfrined a couple of days ago but before i had sex with him i been little cramps here and there but i know when that happens my peorid is about to come on soon but i always count the days up when my period comes on so i'll know next time when it will be coming on next month but when i did it was pose to come on the 6,7,8,9 of this month it's now the 11th and it havent came on yet i'm still getting cramps here and there so i'm guessing it will come on but here's my question. before i had sex my stomach been hurting and i been having cramps thats lets me know that soon my period will come on. i had sex but my period was pose to come on. on the 6,7.8,9 but i havent got it i still get cramps & my stomach still hurt and what not i had safe sex we used a condom it didnt break but im not on brith control. but when u have sex and a fews days later & your period is to come on. on those days but dont does that mean u might be pregnant and if it comes on at a later date or dosent come on that month but next month it does do that mean your pregnant. please anwser thank u