Hey,
Protected anal sex is incredibly unlikely to spread HIV, it would only be possible if the condom broke and this is fairly obvious.
But I understand that testing is a good anxiety reliever. So I’m glad you tested.
4th gen lab based tests are over 95% accurate at 4 week, 100% at 6 week. If lab based Your test at 50 days is conclusive! You have not got HIV.
Even if rapid test your result is 99.99% great news :-)