Weight gaining during pregnancy?

Li
Okay so my starting weight was 224lbs I'm 16w5days pregnant today. 
My weight said I was 224lbs last week. Then 2-3 days later it said I was up to 226.3lbs and now I've been back to eating clean and have been drinking nothing but water. The scale says I'm down to 223.6lbs.
Has anyone experienced this while pregnant before? 
I weigh myself right when I wake up, after I use the bathroom and I always weigh myself naked (sorry for the tmi) lol also always keep my scale in the same exact spot.
I just want to know if I anyone else has had this happen to them. Which weight is accurate? I'm just scared for when I go to the Dr.