Ok I'm 15 I had sex once he pulled out but I'm a week late today I took attest 2 days ago and it was negative I've puked here and there please help

Maybe its just anxiety. But if it continues maybe you should just tell somebody and get it checked out

Of course you do realise that pull out seldom works, and is the least effective attempt at birth control. There are sperm in many of the early fluids. So of course you could be pregnant, it may be nerves, it could be an infection or even a STD, there is no way to tell right now.

Did you use the first urine of the morning, not latter in the day ? That is the trick to the best testing, wait another 3 days, if not, do another pregnancy test.

In the first few weeks of having periods they tend to someties be late so that by itself is not always a cause for worry. The puking is most likely to be because you are nervous and scared and is a normal response. The ngtive pregnancy test could mean that you have gotten some kind of STD or STI or maybe it was just a faulty test (this can happen a lot) I suggest taking another test at a different time of day. I don't waant to sound condescding but maybe next time you take place in sexual intercourse you use some kind of protective because of the sperm that is located in the early fluids and you only need a tiny drop near your area to become pregnant. Try using a condom or going on birth control and never have unprotected sex. Unprotected sex can't just ead to pregnancy but it can also lead to many different STDs and STIs, some of which can be fatal.
Stay safe