I still feel I am pregnant

What you should do is this: 

1. STOP HAVING SEX
2. STOP HAVING SEX
3. STOP HAVING SEX
4. STOP HAVING SEX
5. AND FINALLY, STOP HAVING SEX.  

At 17 you can't even see the things you are ignorant of... you don't know what you don't know.  You can't even see the things that you will have to deal with.  

If you are pregnant, contact a pregnancy crisis center.  At that point, the baby becomes most important.

See your GP (are you in UK?) and get some contraception, having explained your situation and concerns.

Unprotected sex always has the potential to lead to pregnancy.

Most pregnancy tests can be carried out when your next period is due (or at least 21 days after you last had unprotected sex). Is your period due yet? You may have taken the tests too early.

Whenever there is a negative result from a DIY pregnancy test but there is still the thought you could be pregnant, you need to wait another three days before taking another test (it could be that you've taken the test too early).

If the tests were done at the appropriate time, speak to your GP about it if your period hasn't arrived.

Does this help?