Morning Sickness or Nah??

Please help! My husband & I have been TTC for about 5 months now which I know isn't long. Every month I'm absolutely positive I'm pregnant. As soon as we started trying I started taking the prenatal vitamin. I knew from my previous pregnancy that taking them at night was best so I have been taking them the same way, same time every night. I've not had any problems or sickness. Then on Tuesday night I woke up in the middle of the night incredibly nauseous. It took a lot from me to not run to the bathroom to throw up. I fell back asleep eventually, woke up with a tender stomach and a headache. Then nothing Wednesday and then last night, same thing. Got incredibly nauseous, it was so bad I was afraid to open my mouth to ask my husband for water. I don't know if this is MS and it's just early or if it's he prenatal for whatever reason. I had really MS with my daughter but that was 8 yrs ago! Please help! I need opinions!