Meant to say and egg to implant...
4 dpo ur not even pregnant so far too early to test. Takes at least 10days the egg to fertilize
It normally takes 7-10 days for ferrilized egg to implant and when that happen the pregnancy test will then detect your hcg. It was probably too early since it was only 4 days after ovulation. Hope this helps sis. Though I've never had it done sis.