Anxious I could have been poisoned...drank from bottle with safety seal missing

I got a bottle of a liquid anti anxiety supplement from the store and I noticed it didn't have a plastic safety seal. I took one serving and then started to worry that maybe I shouldn't have. I called the store and they said the other bottles are sealed. This happened a while ago but I still I can't stop worrying that someone might have poisoned it or put something dangerous like drain cleaner in it. Am I being paranoid? Is there a more likely explanation for no safety seal being on my bottle when the other ones were sealed? I know it's probably highly unlikely and I've gotten a little better but I can't seem to put the incident behind me :( Can anyone help..

Thanks!