I've never experienced anything like yours with all my 4 kids. Maybe you're already dilating? Spotting shouldn't soak your pantyliner. It should be just a small amount of blood. Like your gynae says, count your contractions and baby's movements.
Usually after check with will bleedings, it’s normal. My all 3 had this too, around after 1-2 weeks or lesser will have mucus plug coming out. But still every birth is diff, hence every labour signs are different too.