Miscarriage

So its been like 6 days and i was supposed to get my period but i had taken a pregnancy test because i had sex and he didnt know if he dpulled out on time🤦🏻‍♀️ and i took 3 two came out undefined and one came out positive. So i just decided to wait for my period but on Friday i had the worst pain of my life and i thought it was cramps until i went to the bathroom and it was a lot of blood i knew that wasnt normal it was a big cloth of blood. i knew right their i had a miscarriage. now ive been talking to the dude that im with about it. went to go get checked and everything. but im not sure how to feel ive been feeling so down i have nightmares i feel like it was my fault i feel very very sad and i cant even express how i feel