Need advice please

I have had 2 easy pregnancies and deliveries one in 2009 and one in 2014 in 2016 i became pregnant and had a missed miscarriage the baby measured 8weeks and had not heart beat and I was supposed to be 11weeks i had a d&c done. We started trying again in 2018 and couldn't get pregnant finally end of 2019 i got pregnant 3 times back to back miscarried all 3 before 5weeks. I got diagnosed with endo and 1 blocked one partial blocked tube in March 2020 had my laproscopy surgery in May got pregnant again last month and once again lost it before 5weeks. We had time to get blood work done at 4weeks my hcg was 34 and progesterone at 20.9 and 3days later my progestrone dropped to 2.9 and hcg to 15. We have checked my progestrone at 21days of my cycle it was 13.5. This time I went in after this miscarriage he told me next time I get a positive test I need to take baby aspirin. What do yall think could be the issue or has anything else had something similar? A fertility specialist checked my uterus and said the blood flow and everything was spot on.