Possible miscarriage??

I have Endometriosis and PCOS and have ALWAYS had bad And painful periods my entire life... After years of trying to get pregnant to include fertility, I had no luck. Finally realizing that I would probably never have the opportunity to carry and have a child of my own I kind of "gave up". I met my now husband who has 2 beautiful children that I'm so great ful and thankful to call my step children and Love them as if they are my own. Well, to our surprise we got pregnant actually right before I was ready to have a complete hysterectomy and be done with all the pain and issues. She will be 2 in August and is an absolute miracle! Well, this past weekend I feel like I may have had a miscarriage... My husband and I had sex late last week, afterwards I went to the bathroom and had some spotting that was very bright pinkish red. It happened a little the next day but then stopped. Then, Saturday morning I started pouring and HUGE clots and terrible pain in lower stomach and also my lower back. Very nauseous and not much of an appetite and very tired. It continued through Sunday. Yesterday had some spotting and mild cramping and then today very light bleeding (more dark colored now) and mild cramping. Does this sound like a miscarriage or has anyone else experienced this? Thanks for taking the time out read and also any input :)