What Causes Body Pain, Vomiting And Spotting During Menstruation?

hi am 23 yers old and i meet my bf two days before my period starts and i got at the same day red blood after two days my all of my body statrs to be painfull and all of my body was in a pain then i went to the bathroom and i got all of wiered things raise in temper and i forced my self to vomite and that last for two days more during this my period was just blood spots ... after eight days i got pregnancy test and it was neg... can i be pregnant please help.
note . am virgin