Hi, I just noticed a few days ago that my toilet has started to bubble when I am in the shower. It has been doing this for a while when the washing machine starts to drain out. We just had the septic pumped out about 2 months ago. Also in the last 2 weeks every so often when we flush the toilet it wants to overflow. Any ideas on this. We have replaced the seal on the toilet about 4 times in the last 6 years. The septic was put in (I think) in 1993.