fermentation lock question

I'm brewing my first ever 5 gallon batch of beer using a kit from Brewer's Best. I used distilled water for my fermentation lock, filled it to the "fill line", and noticed that once it started bubbling a small amount of water dripped down the lock and into my fermenter. Is this something I should be concerned about introducing bacteria? I figure I'll let my taste buds do the deciding when its all said and done, but for future reference I'd like some opinions.
Thanks!

Nope, you'll be fine. For future reference, you could be better served using something like starsan or vodka instead of water for the lock. Just adds another barrier of sanitation. But don't worry about it for this iteration, and enjoy!

Relax, it'll be just fine.
I just started using vodka in my airlocks, just bought a cheap half pint to only be used for that.

Sounds good, then.

Also, be aware that the reason liquid gets "sucked back" through the airlock is because the pressure has dropped inside the fermentor, usually because its temperature has dropped.