Your symptoms are suggestive of an impending labor. Backache
could mean dilatation of the cervix
and perception of fetal movements low down could mean descent of the presenting part in the uterus
. You should note the fetal movements, take absolute bed rest
in left lateral position, observe for any bleeding or spotting and draining and report the matter immediately to your doctor. Please get further instructions from your doctor. Wish you safe motherhood.