Hoping !!

My husband and I have a soon to be 15 month old son ! We have been trying for a two months to conceive another child.. However nothing this far my periods have been averaging 27-28 days each cycle ! And today is day 29 of this months cycle and still nothing ! I'm soooo anxious and ready to find out ! I hate this feeling ! I hope we don't get disappointed 😩😭😔 but I took a test today and it was negative ! I'm only two full days late ! How long did it take before you all got a positive ?