Possible Pregnancy: Understanding Delayed Periods & Negative Tests

Question
hi.i am 15years old.firstday of my last manstural period was 1st of february,but importantly it was also delayed as my second last period,s first day was 21 of december.i had sex so many times in january. i had test on 30th jan which was negative.my question is that do i need not to worry about getting pregnant as my period is normal(7 days) although it was a little late + my test was also negative which i did 2 days before start of my delayed period.does starting of period means i will not get pregnant as i had no sex after starting of my period.thank u.

Answer
Once you get your period, you cannot be pregnant. If you got your period on February 1, and it was a regular period, you are not pregnant. If you miss a period, the best time to take a pregnancy test is seven days after missing your period.   You may have irregular cycles and should probably be started on birth control pills in order to regulate your cycle. A cycle is considered normal if it is 21-35 days from the start of one period until the start of the next periiod. See if you get your next period in March. If you do not get your period by March 10, take another pregnancy test. If it is still negative, you definitely should go on birth control pills. At the age of 15-21, most women have "anovulatory" cycles and can benefit greatly from birth control pills that will regulate the period to a 28 day cycle. Discuss it with a gynecologist.