A while ago I heard a BBC radio broadcats from their health report. There is some concern with the use of those over the counter self test kits for malaria, if the result is positive that is correct.
However, now some of the negative resukt are false as the person using the test has not waited enough time for any disease to develop.
I do not think that they mentioned an exact period to wait between being bitten and taking the test.
I cannot find the report either using google or the BBC
Here is a Unicef item about these devices but it is a few years old