Birth Control plus no period

Patient: I have currently been a new form of birth control for the last 4 (maybe 5) months and have not had a period. I was originally switched to this pill after having a period that lasted about 3 weeks.I am currently sexually active and am worried about the issue of not having a period. I have taken 3 pregnancy test through out this time testing for pregnancy and it turned out negative. I have not yet taken one for this month.I take my pill everyday at 6pm.Could I be pregnant? Why am I not bleeding? Should I be worried? What should I do?

Symptoms: No period
under a lot of stress (maybe unrelated)

Doctor: