spotting at 6wks 2d by ultrasound

Hello moms.. this my 1st pregnancy.. Ask ko lang how many days dapat nag lalast ang spotting or mild vaginal bleeding? Ngpacheck na ako this sat and by tvs embryo pero wala pa heartbeat ? pnag rest nya ako from work and may meds.. Dapat daw next check nmin sa sat ulit may heartbeat na tlga ? meron pa din brownish/reddish spotting/discharge at times pag ngppee.. Gano kya eto ktagal? Thank you..