CAN I BE PREGO

I NEED SOME ANSWER PLAZ HELP MY LAST PERIOD WAS JAN 27 AND IT NOW MAR 1 AND STILL NO PERIOD I HAD SEX A FEW DAYS BEFORE AND THE DAY BEFORE IT STOPED THINKIN I WASNT ON IT STILL AND THEN BEEN STILL HAVIN SEX SINCE AND NOW I BEEN FEELIN SICK,HEADACH,BACKACH,LITE HEADED,DIZZY,NAES,TIRED,EMOINAL,VERY IRRATED,BLOTED. MY BF HAS NOT LIKED THE WAY I BEEN TREATIN HIM LIKE WHEN HE WANTS TO GET OFF THE PHONE I ALWAYS THINK AND SAY HIS GONNA GO TALK TO SOME OTHER GIRL AND JUS FEEL REALLY JELOUES AND I DNT LIKE IT HE DOESNT KNW THAT I BEEN THINKIN I COULD BE PRGEO SO HIS THINKIN IM JUS DOIN THIS AND IT NOT FEAR TO HM IM DOIN THIS TO HIM AND I DNT WANNA LOSE HIM BUT I DNT KNW HOW TO TELL HIM WITOUT HIM STRESSIN MORE PLAZ SOMEONE HLEPO