WELL MY BOYFRIEND&&I HAD SEX ONCE IN JUNE 2009 AND 6 TIMES IN THE MONTH OF JULY 2009 EACH TIME HE CAME INSIDE OF ME. THE FIRST DAY OF MY LAST PERIOD WAS JUNE 21 WHICH MEANS THAT MY NEXT PERIOD SHOULD HAVE STARTED JULY 23[28 DAYS LATER] HOWEVER IT IS NOW AUG 1ST AND I HAVE NO SIGNS OF IT AT ALL. I USUALLY GET DULL CRAMPS 2 DAYS BEFORE IT STARTS, BREAST TENDERNESS AND THE LIKE BUT NO SIGNS AT ALL. I TOOK ONE PREGNANCY TEST ON JULY 23 IT WAS NEGATIVE AND I TOOK ANOTHER ON THE 31 ST STILL NEGATIVE. HOWEVER ABOUT A YEAR AGO MY PERIOD DISAPPEARED FOR 3 MONTHS STRAIGHT BECAUSE MY HORMONES WERE IN BALANCED IN MY LEFT OVARY OR SOMETHING LIKE THAT SO THE DOCTORS PUT ME ON BIRTH CONTROL I TOOK IT FOR 3 MONTHS AND THEN STOP BUT THAT WAS A YEAR AGO. COULD IT BE POSSIBLE THAT I AM PREGNANT BUT MAYBE MY HORMONES ARE NOT STRONG ENOUGH TO BE DETECTED?