Ur period was due 26th of august right?
If so then yes you can test.
You can test from the day of your missed period, or when ur period was supposed to start in ur case.
The small amount of bleeding could very well be implantation bleeding.
When I found out I was pregnant, I started bleeding about 3 days after my period was due, and thought I was having a miscarriage, but then later found out I was having twins...
Your better off just doing the test