If you are new to Freecad, switching from other software, etc., you may find you're self in a tricky situation while you are in sketch mode. What I mean by that is the habit we get overtime, while we are in 3D mode and rotate things around.
As in the following image, we can see how the default sketch does look like. "Top" view, of course.
But, as I mentioned, we may accidentally move the mouse, while holding the buttons, and orientation is "lost", so to speak. The reason is, sketch mode, by default, does not have a fixed orientation. Same situation is within other software.
So, if you got your self in the situation as in the image below:
all you have to do is to go to the Sketch menu, and select "View sketch".
>> Sketch -> View Sketch
Or, simply click the same icon, which is available on the toolbar.