Contractions

Last night I was in labor and delivery with pretty consistent but VERY low in strength contractions. They checked my cervix and no dilation, and also ran a pre term labor swab test on me that was negative. I'm home now, but still getting them.. I haven't been timing them or anything, and they don't hurt at all, but definetly feel different and more consistent than Braxton hicks that I have felt. I really don't want to spend hours in labor and delivery again for nothing. 😔 I just want to know what may be causing painless frequent contractions at only 29 weeks ? and even though my cervix hasn't changed yet, does that mean it won't?? The doctor told me to come back if they got stronger, but they haven't.