The first day of my last period was February.7 how far am I?

Go to the doctor, they can tell you... And that is not enough information for us to know. It depends on when you had the unprotected sex "in question"...

the first day of my last period was feburary.7 how far am i?

A rough guide, if your cycles are regular, is to count back three months from the first day of your last period and add a week. This is taking the approach that you ovulated midway through a cycle... which, while it may be the norm, it is not for everyone. This is partly why you have a 2 week window before and after your due date as a "normal" time for delivery. Not eveyone ovulates midcycle... and it can be off once in awhile from what is normal for you.
As Chihuahuamomma said, your doctor will be able to give you a better idea once you have had a scan. Even with that, it is not exact and you will still have a fairly wide window of time for what is considered normal to have your baby... very few babies are actually born on their due date. Statisically, first babies come after the due date. Some feel about an extra week should really be added to gestation, for first time mothers especially.

Oops, sorry... I misread your post. It is generally thought you ovulate midcycle, or about two weeks before your next period. As I mentioned previously, not everyone follows this pattern however. Often due dates are counted from the first day of your last period because it most often is not known exactly when a person happens to ovulate. Counting from this day, however, often means you aren't actually pregnant the first couple of weeks... this is using a gestational age, and again why you have a 4 week window of time for normal delivery. Fertilizational age is more accurate as it counts from when you actually ovulated.