Pregnancy...late period?


So my husband and I started trying to have a baby last month. My period is late by two days so I took a first response pregnancy test (suppose to show up to six days early or whatever) and it says negative. My last ovulation was last month the 22nd and that’s when we tried twice in one day. Idk if my period is late because I’m thinking about it stressing over it or I could be pregnant and it’s not reading? How long does it usually take for a test to show positive?