😩😩lord why me?

i’ve posted a positive test yesterday , i was indeed pregnant. mine lines were not getting darker and today they are negative. so i’m indeed having a chemical. i say the reason i conceived is because of preseed i give it all to preseed. it really hurts my soul. especially after having a miscarriage at 9 weeks in February this was my first time seeing a positive test after. i’m just so discouraged on why i keep getting pregnant and miscarrying. i had one miscarriage and two chemicals. ( i also have a daughter already with someone else) any possible reasons why? any things i can do to stop it from happening? could it be his sperm?