There is no restriction on sexual activity unless either the Perinatologist or I have told you otherwise. Sex cannot hurt your baby or cause a miscarriage. It can sometimes cause some spotting and cramping which is normal. Later in the pregnancy, semen and nipple stimulation can help initiate labor. Walking, drinking castor oil and other wives tales have never been shown to induce labor. Walking will make you tired and hurt more, while castor oil will give you diarrhea.