Fix symmetry for retopology

Hi I’ve got a model. I was going to attempt my first ever retopo but…

I seem to have broken the symmetry at some point.

Is there any way to align the model so that I can use the mirror modifier during the retopo? You can see its mirrored where the legs meet but then everything else is shifted to the characters right (the left of the screenshot)

Should I be posting this to blender.stackexchange rather than here. I’m pretty new to this website.