I might have drank from an unsealed bottle

Hi guys,

I recently bought a drink, and I noticed some weird thing about it:

1. I can't remember if it was sealed or not

2. There was red residue on the lip of the bottle, but the drink was purple so it might have been the drink itself

3. It had a suspicious, sourish taste.

My question is should I be worried that it was contaminated? Thanks!