Had my septic drained 3wks. Ago .now every time I do laundry I get a fowl oder in bathroom. What can I do thanks

Does the toilet bubble or do you hear a noise from any of the fixtures in the bath> What I suspect is happening is that . After pumping it dry, your septic tank has filled back up again. If there's a clog at the septic tank outlet that would cause your problem. However, It's more likely the drainfield has become water logged and can no longer disperse the water the tank sends it. Get a septic contractor out there to check the drainfield, Good luck, Tom