Pen Tool is not making anchor point on the point I'm clicking. It seems to move a px or two over.

I've been working on a file that seems to not let me put the pen tool where I want it to. It's not a really small file so I don't understand why it's doing it. I've looked at most of the settings but can't figure it out. I need to be able to draw a landscape and van that are technically correct, but every time I try to place the pen tool where I want it, it won't place it in the spot I click.