worrying...

i’m 15 weeks with my twins. had an ultrasound about 2 1/2 weeks ago and both babies were great! heartbeats were 162 and 161. but im always so worried that i’m going to lose my babies. i’ve never had a miscarriage. my first pregnancy was so smooth and with my first i never worried like this. i’m always afreiad something is wrong and i don’t know about it yet. im afraid at my next apt they won’t find the heartbeats. i know i have no reason to feel this way because both of my babies are healthy but i’m always so worried 😞 idk if it’s my hormones going crazy or what but i’m always freaking out :(