I totally agree with the others here. It's not a game! Go and make your BF and yourself get tested for STD's/STI's (Chlamydia, Gonnorhoe, HIV, Syfilis) Also just to be sure you protect yourself as good as possible, if not done get vaccinated for Hep-B.(this is also considered a STD). Not because I think you have a big chance on getting HIV or Hep-B, but as you and your BF seem to do unprotected sex(also with previous partners without testing), it's always good to know your status and that of your partner! just to add on: Chlamydia and Gonnorhoe are much easier to chatch than HIV.
If you're not sure stop having unprotected sex. If you have already been with him for 3 months or over, and if you are sure that he has been faithful to you during your time together, just get him tested with an antibody test any time now for a conclusive result. You may want to get tested for his piece of mind too.
Hi... HIV is not an odds game... The only way to know is to get tested. If you're worried about your partner.. Get him tested... If you're worried about yourself and trying to link all these questions to yourself... Please read the reply given by b23121 in the other thread..