hello,first of all considering you had protected intercourse (use of condoms)with your partners,any of them had hiv infection then if you had it protected without any failure then,there are less chances that you have got hiv or STI(sexually transferred infection) from any of them.But the possibility of hiv infection or any sexually transferred infection without using protection is more or i would say can not be denied.The episode of rashes over your body can be due to sensitive skin,dry skin as you were adviced cetaphil and it was gone after taking medicine.you mentioned that you had sore throat,that can be due to any viral/bacterial infection,and after treatment it might have gone.You underwent prenatal antibodies coombs test which came negative it means there are no antibodies attached to your blood cells.(Antibodies are products produced due to any kind of infectious agents in your body).You said you have no other symptoms so far but Still if you are in doubt I would suggest you to undergo ELISA test.I would suggest you to contact a physician in person and talk about it,it ll be better to do your physical examination and then if the physician advices then go for the test.Or else there is no need to worry.Hope this clears your all doubts.