Gibber

Hey There...
I would like to first off say that I am 5'8" - 180lbs and have been training for 16 years.
I am looking at cutting some weight and have researched many different methods and am only interested in orals. I have been taking E/C/A for the last month and noticed a little bit of fat loss (1-3 pounds) but nothing crazy. Therefore, I have started taking Clenbuterol (50mcg) tabs. They are from a newer company called "Atlantic Labs?"
I am a little unsure as to how they are working. Day 1 - I took half the tab in the morning and half in the afternoon. I experienced no real jitters yawned alot and had a decent workout. Day 2 (Today) - I took two tabs in the morning...Went to the gym with a standing heart rate of 110bpm. Felt a little wired but nothing overwhelming. I have been yawning all morning and yet to experience any real jitters or headaches.
I also have had no trouble sleeping at night. However woke up once with a slight headache. My body is slightly sore but I have been hitting the gym hard for the past week.

My question - Is it possible to be a little immune to the clen as I did not take any time off the E/C/A stack? Is it possible my tolerance may already be high if I have cycled E/C/A for the last 6 months with 8wks on 2wks off?