I wanted to know if any one can give me some clarity or some suggestion to the question below.

My breast usually get soar about a week before my period. But, this particular month, they have been feeling sore three weeks prior to my expect period. My nails are getting long and not breaking when they usually do not grow at all. I am on birth control and taking on a regular basis. I sometimes take my pills really late after my usual time. While doing some research for this I noticed that the research is indicating that I may be pregnant but I doubt it due to me being on birthcontrol. Can anyone please give me some guidance?