I'm 40 years old and I'm having some serious blood clots during my current period. It is extremely uncomfortable and somewhat embarrassing I'm wondering if this a sign of early menopause or should I see a doctor?

Time to see your doctor and have your hormone levels checked as well as iron levels.

At 48, I'm well into perimenopause (pre-menopause). I read that lack of estrogen leads to uterine lining clotting, as opposed to normal thin blood flow. This must clog things up and cause more cramping, but no flow on your heaviest day. I took a dose of Estroven, found in most grocery stores, drank a couple of cups of Soy Milk (Silk brand) and took one aspirin to help thin out the clots. The pain of the constant cramping left within 4 hours, and within 12 hours, my period resumed and the clots started passing. I also had my first "hot flash" that day before starting the soy products, so looks like my estrogen levels had fallen to a new low. Small clots started around 40 and have gotten larger over the years.
As others have described this lack of estrogen and cramping, I agree it can be debilitating. Since soy replicates estrogen and since HRT (hormone replacement therapy) has well known side effects, I am minimizing taking soy to only when really needed. I may take one Estroven a day during my period and 2 on the heaviest day, supplemented with a cup of soy, until I no longer have periods. Others have written that D&C options didn't work. Read about ablation but would like to avoid any surgical procedures, if possible