Totally normal! With this pregnancy I'd have 3 days of horrible sickness, then feel brilliant for 2 days only to be hit with another day of sickness, then 3 days of feeling fab and so on, totally unpredictable until about 7-8 weeks when I just felt rotten all the time until the 2nd trimester..

Lots to look forward to! Enjoy the days you feel great! Good luck!