I smoked weed Sunday and I had four hits how long with it take to leave my system

The amount of THC (and metabolites) in your system are very dependent on 1) pattern of use as well as 2) dose. If you smoked Sunday it is in all likelihood cleared. i.e. single use + low dose.

This is very different from higher and more frequent use that can result in detection for much longer periods.

Ref.

Perez-Reyes (1982) cited in Drugs & Human Performance