Irregular sickness?? Help ):

My fiancé and I had sex almost two weeks ago. I rode in a car for 17 hours from TN to FL this past Saturday and I feel like I can't get rid of the motion sickness. Every time I eat I get nauseous. I don't feel hungry until I eat but I only eat 3 meals a day with a snack if I feel up to it. I'm also four days late for my period. I'm so tired of feeling sick. Help! ): ):