15 days late on period, pregnancy test is negative and am taking junel fe as birth control. should i be worried?

Not necessarily: It's a good idea to speak with your doctor about missing your period, but being on a birth control pill can alter your cycle. Usually a pregnancy test would be positive by now, but you may want to repeat it in another week.

Depends: If you had sex since your last period, you may wish to repeat the pregnancy test in 4-5 days. Use first morning urine and follow the instructions for the test carefully. Alternatively, you could get a blood test for HCG.