Why is birth control making me throw up?

My Dr is having me take sprintec for 9 weeks to regulate my cycles, so we can move on to medicated cycles afterwards and hopefully get pregnant. I have never taken any birth control before and I am currently going into week 3.

When I first started taking it, I had really bad headaches, bloating, dizziness, and nausea. The side effects were terrible. Most if that has settled down, but I'm still feeling nauseous regularly and sometimes throwing up.

I take the pill first thing in the morning, feel nauseous throughout the day, and whenever I do throw up, it's always at night right before/after I go to bed. Why is this? Is there anything I can do?