Welcome to our Forum. You have no reason for concern. Even before your test results were available, your risk for HIV is low. the chance that your partner, as a heterosexual male in North America had HIV is very, very low (less than 1 in 1000) and even if he did , the risk of getting HIV from a single act of unprotected vaginal intercourse were also less than 1 in 1000. Thus, statistically, your risk from the single exposure you describe was less than 1 in a million even before you were tested.
Then you had a HIV ELISA blood test at 3 months. This is definitive proof that you did not get HIV from the exposure you describe. You do not have HIV, you do not need further testing and your husband is not at risk.
You can put this all behind you and move forward. Take care. EWH
If anything I think you'll be glad you found this site. I'm certain that dr. Hook or dr. H will help calm your fears. You had a negative test at 3 months. I think you are conclusively HIV negative, especially since the odds were low that your partner had HIV in the first place.