Rapid tests are just a gamble if you want to save time/money/exposing others if you end up being positive.
If you're negative, you then have to get the actual test, but if you're positive you can probably start isolating now.
If you're negative, you then have to get the actual test, but if you're positive you can probably start isolating now.
If you experience symptoms you should start isolating, regardless of the results of a rapid test.