so scared but so happy

I have been feeling really off lately I've been taking pregnancy test since 6 DPO because I'm impatient all negatives which I figured it would be. I'm so nervous about getting pregnant again because in February I had a missed miscarriage and in May I had a chemical pregnancy. I've been super stressed lately because my best friend just passed away on Father's Day. and then I decided to take a test this morning and here it is.

I'm honestly still in shock. I'm so scared of something going wrong again. I'm so happy but the fear I feel is taking over the happiness. I don't even know if I want to tell my fiance or not because we were so happy the last 2 times and then we're just left with such disappointment. but at the same time I don't know if I can go through this alone. I need some advice.