3-week Mega Period! (may be TMI for some)

I gave birth in July and breastfed until my milk dried up in January. When I was pretty well dry I started spotting (late December/early Jan.) and had a 10-day, super-light period in late January. I started using some progesterone cream to get my hormones back on track.
Then nothing for weeks. I hadn't been taking my BBT, so I don't know if I ovulated. March 11 I started spotting a bit, and by 3/12 it was full, heavy, regular day 2 stuff for me...I thought. My periods never used to last more than 6 days. Now it's been almost 3 weeks (20 days today)! Most has been what I used to consider "heavy bleeding", and some days worse than I believed possible--almost like day 1 postpartum with lots of tissue (not clots). I talked with an OB and they said it was probably hormonal, as my TSH and such were OK. I figure I was building a thick lining for the last 8 months and this is the first time it's really shed. Still, I'm ready to be DONE! Taking my temp, and at least haven't ovulated during AF. We're TTC again, so that would be a real bummer.
Oh, after 12 days of heavy bleeding I did some research into herbal emmenagogues to try to get things going. I took an infusion of raspberry leaf, nettle, and red clover with ginger juice and several drops of blue cohosh tincture, and this really jump-started things. Before taking this I had been bleeding lots but very little endometrium was being shed (I use a cup so I can monitor). Afterwards, I started losing more tissue than I thought it was possible to have! I think the reason I hadn't gotten PG yet was that there was too much lining for the sperm to get through!
Now I'm down to little bits of dark red blood, like what my days 4-6 used to be. Hoping to be done today!