I recently had sex 3 days ago on the 1st full day of my period (my period came right before I went to bed the previous night). We had unprotected sex, but used the pullout method. Ever since then, I have been feeling super crampy (made my period cramps worse), and upset stomach to the point of feeling like I am going to throw up. Just today, I have finally thrown up, but still feeling sick to my stomach. What could this be?