Some women lose their mucus plug several times during pregnancy, but it can be a sign your cervix is dilating and combined with the BH and change in your behaviour (from your OH's pov) it would be unwise to not ask the hospital to check you out. It could be that you have just lost a little bit of plug and your body will generate more, but at your gestation it's not risk worth taking for the sake of avoiding a trip to hospital.