3rd trimester anxiety

I am 28+1 weeks with my first baby and scheduled for my first “3rd trimester” antenatal appointment this coming Friday. The last 2 weeks I have found myself with increasing anxiety. I have had pretty frequent Braxton hicks (or so I think that’s what they are) no pain just a heavy band like feeling across the bottom front of my abdomen. This has been happening since I’ve been able to feel him moving (anterior placenta) I notice when I touch my bump sometimes it’s firm and others it’s soft I know it’s probably from baby positioning in the uterus, but can’t help to panic about early labor. The “Braxton hicks” or that heaviness feeling comes and goes irregularly (I’ve been keeping track just in case) and happens pretty frequently. I’ve had an extreme fear this while pregnancy about miscarriage and stillbirth as this is our miracle baby. I know I’m in 3rd trimester and will start to feel different things as my body prepares and plan on asking my OB about it on Friday. I have had no other changes or issues other than back pain. Anyone else can relate to this ? Im sure when he’s here I’ll have a whole new set of worries 😫