agree with this. most likely main line is clogged.

I had a similar experience. Check out the cleanout plug (white PVC) outside of the house and you may found water clogged there. If that is the case, use snake from there to unclog. But sometimes the outside sewage pipe clog may be caused by root. The clogging may come back again and again. You need either fix the PVC pipe so no root get in, or use root killer (from lowes or HD) every spring and summer.

Good luck!