There is Prep. It's a medicine that is expensive, but will help prevent you from getting HIV, when you bareback. Talk to a doctor about it. Also, it's more safe to be with someone who is poz, but undetectable, then someone who say's their negative, but haven't tested after their last fuck. In a study that was done on mixed couples, one poz, one not, who barebacked, there was no case of the negative partner getting HIV from their partner. There were some cases where the neg. person became poz, but through testing the HIV DNA, they found that it was not from their partner, which means it came from them sleeping with someone other than their partner, who was poz. But if you absolutely don't want ANY chance of getting the bug, then use condoms, and pray, or don't have sex.
That being said, there is nothing like taking the seed of another man. That's how it was meant to be, and it will change you for life, even if it doesn't make you poz. Once you've felt another man shoot inside you, you won't want to turn back. It's all you'll desire. Trust me, it's worth it.