Stopped my ortho-tri cyclen lo pills after only taking the first two pills of the pack. had break through bleeding 2 weeks later. is pregnancy possible?

It's Possible: If you were having unprotected sex, yes, it's possible. But sometimes after being on birth control pills for a period of time can alter your bleeding pattern and cause spotting. As you only took two pills, I am not sure that would be enough to cause this but it's not out of the question. If you are concerned, take a pregnancy test and/or consult your doctor.