Changing nipple bar

I got my nipple pierced a few months back and I love them. I recently bought a pair of personalized barbells with my boyfriends name and I was gunna change them and surprise him. I was fiddling around with my left piercing barbell seeing how they unscrewed. As I think I’m unthreatening one ball the other pops off and the barbell comes out. I got it back in super easy with no pain, but now I’m paranoid that the ball is gunna fall off (I’ve tightened it as tight as I can). I haven’t even messed with the right barbell. I don’t wanna change them just yet cuz I don’t want something similar to happen whilst I’m at work or something, but when I do soon I wanna make sure it’s secure.