Yes if you saw a mostly full moon Saturday night it did appear larger and brighter than usual. It was your first glimpse of the first 2020 supermoon which is at its fullest on Monday, March 9 at 1:48 p.m. EDT. However, it’s fine to look for it Sunday night.
The reason it looks larger is because its elliptical course brings it closer to earth on March 9.. The close point is called the perigee as opposed to the far point which is the apogee.
At 222.081 miles from earth it looms large but the next full moon an April 8 will be even closer at 221,851 miles.
This March supermoon has several nicknames including the “Worm Moon” because worms are said to begin to come out of the soil about this time.