To find out whether or not the data file is growing (autogrowths) you can use the Disk Usage report. Right-click on the database, go to reports and select the Disk Usage report. If you are not on SP2 or greater - the reports are in a different location but still accessible.

When the database was shrunk - all of your indexes were fragmented. I would schedule an index rebuild when you have the time, and make sure you have at least 1.5x the largest table available space in the data file. If not, manually grow the datafile so you do.