What Causes Sore Breasts, Nausea And Tiredness During Menstruation?

Hi I ve been experiencing sore breasts nausea tiredness then I got my period ? Normally goes for 7 days only went for 2 and then 3 days later I ve got headaches and wiped brown jelly stuff from down stairs , the nausea is worse . Could I possibly be pregnant or could it be something else