Feeling worried

Nina
I've had miscarriages in the past and I know I should be happy that I'm pregnant now but I'm also a bit paranoid and scared to have it happen again. 
My nipples felt sore all last week and today I woke up and they aren't sensitive at all. I'm freaking out thinking maybe something is wrong. I'm trying to be positive but I'm so scared.
I take a pregnancy test everyday just to reassure myself that im still pregnant. 
Is it normal to feel so scared... Have any of you felt this way? Have any of you felt sensitive breasts one day and then not the next? I've also been feeling mild cramps.