What Causes Vomiting And Low Appetite After Regular Menstruation?

hye this is Bijay from Nepal. i and my girl friend had unsafe sex and because of that she had to take emergency pill 3/4 hour later. she said that her period was late for 5 days and also that she is not having the regular period and less bleeding. after 6/7 days of her period she said that she is feeling vomiting and feeling non-apatite. i am worried if she is pregnant? we were first with out worried as she had period but now we are worried thinking if it was spotting. what shall we do now?