Two of my plants are losing their leaves, finding them on the floor. I am watering on a regular basis.
Why Are My Houseplant Leaves Dropping
I could better answer your question if I knew what kinds of plants you have and how long you've had them, and what kind of light they're in. When there's something wrong with your plants, look first at the soil moisture, then the light, then look for bugs or disease. In general, watering regularly is far less important than knowing about the moisture in the soil, down where the roots (the heart of the plant) live. Learn to check the soil moisture in the bottom of the pot before you water; use an electronic moisture meter. Or a thin wooden dowel or kebob skewer, insert into the soil, pull it up, and run it between your fingers. Depending on the type of plant and the light it's in, the meter should read somewhere between dry and damp, and the probe should feel from dry to dlightly damp. Then you can water again, and water enough that you get a run off from the drainage holes.
Generally speaking, when leaves fall off plants, it's either because the light is too low, the soil is either too wet or too dry, or there is disease or bugs. This article tells you a bit about that: https://www.gardeningknowhow.com/houseplants/hpgen/desperate-houseplants-dealing-with-common-houseplant-diseases.htm