OCD or an innocent quirk?

I'm just curious if this is an ocd symptom or not. If it is I don't believe it's too life interfering and annoys other people more than me. My quirk, as I call it, is that I can not drink the bottom of things. I don't really have a fear of doing so it just bothers me and makes me uneasy. With every drink I have I drink until there is about an inch left and if I'm still thirsty I have to dump the remainder and refill it. It annoys people and I get called wasteful when it comes to my drinks. Once at a restaurant the server emptied the last of the pitcher in my glass and I couldn't drink from it because... it was at the bottom of the pitcher. I wanted to ask for a new glass but I realized that would have sounded... weird.
And I hated when that Signs movie came out. My dad now always compares me to that little girl in that movie- very annoying.

'I'm set if the aliens ever invade our house.'

Haha dad.

But I digress. Is this an ocd behavior? I tried looking it up on the internet but everything I pull up is about babies not eating, alcoholics, or Christianity. *shrugs*

no, i wouldn't say it's a sign of OCD.
as you mentioned, it isn't to the point of interfering with your life.
that is the line drawn where when it is crossed, it becomes a mental illness trait.
most likely you just don't want to drink backwash
nothing wrong with that!