Sign of seroconversion ?????

Hi all,am frm india 3 months back i had unprotected sex with a sex worker whos hiv status is unknown,and exactly after 3 months of exposure i have taken HIV ELISA test which was negative...i have taken tests for other STDs also..all are normal and negative...but am experiencing severe body aches(especially on my both legs and hands)..i have taken tests for thyroid and RA/RF factors which were also negative....and the thing is am experiencing these pains only after my exposure but i have taken 3 elisa tests in 3 months all are negative...am very much worrid and tensed about my body pains...can any one have idea about whts happening with me ....is it a sign of seroconversion after 3 months of exposure...desperately awaiting your response..and thanks for spending your valuble time for reading my article..