You can easily find the searches you have performed by clicking on the "My searches" button and going to "Search History".
'Search History' as the name suggests shows a log of all your searches.
This area is split into 4 sections:
Analytics
This area includes the history of various activities within Analytics (Search, View, Analyze, Export and File Wrapper). For the Search History, you are able to save the searches which can then be found in the Saved Searches area.
Discovery
This area includes the history of your searches and exports performed in Discovery.
Chemical History
This area includes the history of various activities within Chemical (Search, Extracted Chemicals, Chemical View, Analyze and Export).
Login History
This will provide you with a list of your most recent logins and where you logged in from.