though there is no bruising we cannot completely rule out internal injury
, if you are not having any pain abdomen or bleeding per vaginum they are positive factors,
anyhow you once consult gynecologist and undergo physical examination and ultrasound
to rule out the possibility of conditions like abruptio placenta
and to verify the well being of the fetus,
if everything is normal no need to worry and take analgesics for chest pain
with her advice, if chest pain increases better to consult physician once.