Late Period & Possible Pregnancy: What to Do?

Question
i am 14years old.first day of my last manstural period was february 7 and it ended on 12th of feb.most importantly that period was late as first day of my second last period was 29th of december.i had intercourse before 5th of feb and throughout january and december.on 6th feb i did pregnancy test which turned out to be negative and on 19th of feburary i did another early morning pregnancy test and it was also negative.after 4th of february i never had sex.now my questions are; 1)why my preiod was late and according to your calculation by how many days it was late,do i need to worry or will i get pregnant as i had no intercourse after 5th of febuary i-e 2 days before my periods. seconds question is that does continuing of periods although late by few days 100% rules out pregnancy. third and last question should i go for another pregnancy test .now 16 days have passed since my last intercourse.please answer all my three questions as i am too much tense.thanks in advance for ur insight to my problem

Answer
If you had a period on December 29, you were due for your next period around January 25. If a pregnancy test was negative after February 1, you are not pregnant, even if you did not start your period until February 7. If you repeated the pregnancy test on February 19, and it was, again, negative, you are definitely not pregnant and do not  have to repeat the pregnancy test again. Just keep a careful record of the first day of your period, each month. Sometimes a period can be late due to hormonal imbalance and, as long as the pregnancy test is negative, you need not worry.