Extremely light period after miscarriage

It's been almost 6 months since my miscarriage and D&C. Had my first period in August (normal), September was normal, October I think was a chemical pregnancy (came early, lots of clots, much heavier than usual), November and December have both been extremely light, barely 4 days (length is somewhat normal), but just very unusually light almost to the point where I can't use tampons. I brought this up to my OB and she just said I was lucky, but it seems to me that maybe my uterine lining isn't building up like it should. I have an appointment with a reproductive endocrinologist mid January, but curious if anyone has had this issue come up.