There's two panels that's missing here.
The first one is that, she looks back in confusion and sees nothing.
The second one, she looks down and sees, in surprise that she's pregnant.
Sorry there's actually four. The scene originally starts with the girl walking, with a blackened silhouette at the edge of an alley. The second panel then zooms in to reveal sonic. So basically the panel seen in the post is panels 3 to 6.
The first one is that, she looks back in confusion and sees nothing.
The second one, she looks down and sees, in surprise that she's pregnant.