my sister is in her 14 the week, she had a spotting during the 8 weeks and we went to doctor she said it is due to early pregnancy and they gave her a tablet to avoid the risk of miscarriage , 2 days back she had a severe cough at the night and she noticed the spotting in the morning this time the color of the blood was red, after that she rested for the whole and disappeared again, why is this happening