Click on the user account icon (Figure A.) or profile image in the top right corner of the screen, which will open a sidebar on the right of the screen.
Under "Supporter snapshot", you will see "Membership status". It will tell you:
If you are not currently a member (Figure C.).
If you are an active one-year member and your membership expiry date (Figure D.).
If you are an Evergreen member, which means that you are a member and monthly donor (Figure E.). Your monthly donation keeps your membership status up-to-date, meaning you never have to worry about it expiring.