Pregnant With Abdominal Pain And Bleeding. Ultrasound Showing Hematoma. Taking Laxatives For Constipation. Need Polyp Removal?

I had pains in my stomach from early in the pregnancy, then began to bleed heavy after 3rd month. Dr said pains were normal and bleeding was found to be from a hematoma. Then ultrasounds showed hematoma was gone but blood continued heavily. Later an ultrasound showed a polyp. Bleeding was still heavy and I still had stomach pains. One night I went to the ER and was told I was constipated and to take milk of magnesia and other methods to help the constipation. I went to my dr. the next day and he put a solution on the polyp to stop the bleeding. He said the polyp was blocked by a clot so he did the best he could. My stomach felt really horrid from the laxatives for a few nights and the bleeding continued. Each ultrasound showed the baby was in perfect condition. At 18 weeks I had a miscarriage at home. I had been to the doctor before that on the average of twice a week complaining of heavy bleeding, fist-sized clots, and pain.
I stopped work about a week and a half before the miscarriage. While I was working I did almost nothing. I stopped using steps and sat the whole day. In the evenings, I did absolutely nothing.
Why do you think I miscarried based on this info?
I am 37 yrs old and this was my first pregnancy. I am so concerned that this may have been my only opportunity to get pregnant. My family history is early menopause. If I do get pregnant and this happens again, would you recommend staying off my feet completely? Do you recommend removing the polyp ?
Thanks so much for your time