Trusting my body

I trust my body, I trust birth, really I do. I know that in nearly all cases birth is as natural as it gets. That said I'm scared. I've been frequently getting contractions over the last few days. The baby didn't move at all the 25th. I totally blew up at Nathan, I was scared and when I non-chalantly mentioned the lack of movement he responded with the same "no big deal" attitude and I lost it. We talked and he tried to hear a heart beat with the fetoscope (got nothing, but I'm only 19wks) he spent some time with his hand on my belly and all of a sudden the baby kicked. I nearly cried. Since then the baby has been fairly active (Thank you God!) but I'm still getting very frequent contractions, sometimes they are really minor and barely noticeable, other times they take my breath away and I have a hard time concentrating through them. A few have woken me up. I'm exhausted most of the time, but mostly I'm just terribly worried. I usually have preterm labor, but not until about 30wks. Why all of a sudden so early? What could be going on? My cervix is staying posterior and closed but it seems to go from mushy to hard to mushy. I'm actually considering an ultrasound.