I HAD PROTECTED SEX WITH MY PATNER ON 11 AND 14 OF JUNE AND A FULL INTERCORSE ABOUT 5 TIME IN 3 HOURS...HER PERIODS DATE WAS ON 21 OR 22 BUT YET SHE IZ NOT HAVING PERIODS AND TODAY IS 24..SHE IS HAVING PAIN IN HER BACK.....AND I HAD ALSO SEX WITH HER ON 21 OF JUNE ONE TIME WITH PROTECTION.......THE QUESTAN IS THT IZ SHE PREGNENT ..AND Y IS SHE HAVING PERIODS DELAYED ,AND WHT IS THT PAIN PLZZ GUID ME I AM MUCH WORRIED ...........SHE ALSO HAD A HOME PREGNENCY TEST BUT IT WAS NEGTIVE....PLZZZ ANS MY QUESTAN IAM MUCH WORRIED ABOUT HER...PLZZZZZZ