3 weeks ago I had sex with a csw. While having sex the condom burst. Due to my phobia of HIV we did a self fingerprick hiv test, we were both negative. 

I tested at 21 days on a 4th Gen test and it was negative. 

Is a 21 day test reliable and can I relax or do I need further testing. 

I have been having slight shoulder and neck pain, could that be ARS?

Thank you

Congratulations for using a condom for potentially high risk exposures. Too bad it ruptured, but the fact that you have that intent marks you as being at low risk for HIV in general. Keep it up!

With both of you having negative tests soon after exposure, there was no risk of HIV for all practical purposes. You could have skipped the later HIV testing. However, if you feel you need a conclusive test result to relax, you'll need another antigen-antibody (AgAb, "4th generation") blood test 6 weeks after the event. These tests detect around 75% of HIV infections at 3 weeks, around 98-99% at 4 weeks, and 100% at 6 weeks and beyond.

ARS doesn't cause neck, shoulder, or other muscular or skeletal pain as the main or only symptom. Also, it is impossible to have symptoms from HIV with a negative blood test. In other words, your negative test at 3 weeks may not prove you don't have HIV, but it proves conclusively that any symptoms you have are not due to HIV.

I hope these comments are helpful. They should be highly reassuring:  you really needn't worry further, whether or not you decide to have additional testing. Let me know if anything isn't clear.

HHH, MD