'Morning Sickness'

Okay-so I think I just had my first instance of 'morning sickness' but could use some advice.  I am only 4w6d...yesterday (Friday) I was super nauseous at 2 different times throughout the day.  Today I was really nauseous for about 30 minutes before actually vomiting (just a little).  As soon as I threw up I felt instantly better...is this 'morning sickness' or something else?  Please advise!