Brown spotting ?

Carolina

So I had my period on June 20 till June 24 then on July 7 I stared spotting brown for 3 days and it went away then I was supposed start my period on July 25 but that day stared spotting brown just that day btw I haven’t had sex for awhile so I’m not pregnant but Im 6 days late and I’m just really confused is it normal? Should I be worry ?