So it looks like you are close to the end of the fishless cycle.
You had 3ppm ammonia last night, this morning it's 1ppm. Nitrite is 0ppm because all of it was converted into nitrate.
Your PH is slowly dropping because the process of producing nitrate is acidic. It eats away the water buffer. When you get home today, do a 50% water change to restore the water buffer before adding more ammonia. Without large water change, the PH will go down further and it can stall the cycle when it is too acidic.
You might want to add more than just 3ppm ammonia from now on. I was always aiming for 5~6ppm. Not only I can make sure the bacteria will always have a food source, but it can also guarantee there will be enough bacteria at the end of the cycle to sustain full stock of fish at once.
