Why I won't hit under 150

So this week my goal was to get to 150 yet as u can see I only lost half a pound. I was doign good all week. Then on thursday I woke up sick as a dog so I did not go to the gym or even work with my trainer susie. Well when I woke up on friday I was 149 yet I did not get happy because I knew that I was sick. Well on friday I did work out just not as hard since my body was slowly getting over my bug. Then on saturday the weight was 149.5 and I was ok with that. On saturday I was able to go to the gym for 1 hour. On sunday the weigth was 150. Then yesterday was the army wives season premiere so I had dinner at a friends house and had 3 brownies. Which I know is bad but I figured I could have a small treat. Well that small treat made me gain back a pound. No needless to say I am stuck at 151. While I am happy that I have lost half a pound I wish I could get below 150. I knew losing weigth would be hard yet I did not think that I would get less than 15 pounds away and not get the last little bit off.