N.P.
It really varies woman to woman. Some references state as long as you are nursing 100% you will not get your period... but this isn't necessarily true. If you THINK pregnancy might be a possibility, I would purchase a home pregnancy test. If not, your body may still just be adjusting and since you are nursing/supplementing it could be a few more months. You might also want to check with your ob/gyn for any other concerns.