I'm on water catchment and I have a water pump to pump the water to my house. Usually, when I use the shower or toilest, the water pump turns on and brings pressure up to 40/60, then shuts off. This morning, after using the toilet, the pump went on, but kept on running (I had to pull the plug to shut off)

Any answers??

Have you checked to see if the pump has lost its prime?

What is "it's prime"?

I am assuming you are using some sort of jet pump. Check out this article.

https://app.qleapahead.com/rtp/LibraryGet.aspx?asset=85730,63