RDS Free Storage Space is going down

Being someone requiring additional learning curve with AWS RDS and have been trying learning from available AWS RDS documentation, I would appreciate any technical direction to clear some of my queries in regard to understand dynamics with AWS RDS Storage.

The project I am working with uses SQL Server and has quite a limited users with less amount of data at the moment, but I have been observing my RDS storage gradually being consumed over time span of two weeks and I am not able to figure out what actually is consuming this storage as the DB seems to have very less volume of data(92 MBs as attached in screenshot below).

Database&Logs Size

Can anyone have a look at curve and guide which areas I might be missing looking into insights? Is it only DB or any other factor contributing reflecting the overall storage?

Free Storage Graph

Thanks in advance