Progesterone, hematoma 9 weeks

Just found out we are 9 weeks pregnant with #4! US yesterday showed a small subchorionic hematoma. I had one with #3 as well but no problems with the first 2. My doctor also said my progesterone levels are a bit low and would like to supplement until 13 weeks or so. Anyone else had this?

I would also like to note I have a 7 months old and I did have a mild period 5 weeks ago followed by some mild spotting a week later. I have cut back on breastfeeding in the last two months due to other complications with it.