Started my 2nd trimester and Scared shitless

Gia
So with my previous pregnancy I was only 17 years old and had never even made it to the second trimester as I had lost the baby at just 5weeks, I've had such high hopes for this current pregnancy and the fact I've made it to 4month's literally makes me so happy but then I see all these posts where people have lost their babys during the 2nd trimester as well and it just puts me on edge all over again, i keep talking to my belly trying to bargain with my baby to keep growing healthy and strong so he or she can enter this world healthy and alive but I am actually really scared, to the point where I have bought a fetal doppler and even after hearing the heartbeat I sit there and think oh no is it dropping was that really the heart beat etc which ik is my paranoia but are there any ways I can feel more at ease?