Question

Okay, so I have been taking Fertilaid for about a month now and my monthly visitor is officially 6 days late.  I have taken a test on day 2 of being late and it read negative.  I am not sure if I am late because of the fertiliad screwing with my body or because I may have ovulated later than I thought. But, how long do you wait without a period before consulting a doctor?  Do I quit the fertilaid. (Fertilaid is an all natural vitamin that has all you are supposed to need to be able to conceive>.....thought Id give it a shot.)