Boy Am I Confused!

Ok, try to follow this. 2 weeks ago I worked out 3 times with my trainer and was very good on my diet. I lost a crappy 2 pounds (don't tell me that is good the effort was worth more!) The next week I stuck to my diet but only did cardio 1 time for 30 minutes. I gained the 2 pounds back. Ok, so I should not have lost maybe but to gain? So, I decided to take the weekend off and eat what I wanted. I did not pig out but did have ranch on my salad and bacon, and for Sunday dinner I had potatoes with a little butter. (ok, I had seconds on the pork with gravy too) Well I figured with that bad behavior I would have gained more - can you believe it - I lost a pound between Friday and today! So today I started fresh and worked out and stuck to my diet and everything. I will just keep going and my goal this week is to get to the 50s! The 60s have been hard and can not wait to see them go!!!