Help! Can someone tell me if I'm pregnant?

Ok so I had unprotected sex on June 3rd...I took a pregnancy test on the 19 and the 20th both said negative..then I took two more tests on the 22nd and 23rd..these also said negative. I have no pregnancy symptoms and in fact I dont really have an appetite. I took the tests because I thought my aerolas were getting darker. Can someone tell me if I might be pregnant? Also the last two pregnancy tests were first response if that helps.