I THINK I HAD A MISCARRIAGE?(long post)

I got off my nexplanon in April after having it in for almost three years so I'm still figuring out my periods. Last month I spotted several days before my period....thought it was my period but it stopped for a couple days and then I had my actual period. I used to never get cramps when I was a teen and last month they were so bad I had my knees to my chest in bed and cried....I went to the bathroom and when I whipped there was a blob of tissue. I've had clots before and this looked nothing like a clot. There was also a little more tissue that fell into the toilet bowl while I was peeing....I think I may have had a miscarriage because I looked up early miscarriage pictures and the blob that came out of me looked the same.......what do I do? :( I have told my mom she didn't seem worried but she also thought I had a miscarriage. I don't want to tell my fiancé because he's gone through loosing a child once before and I don't want to break his heart. I just need some advice