Pregnant??? Help.

I really need y’alls help. I’m 3 dpo and I had sex 10 days ago. He used a condom and pulled out and nothing went wrong. I keep thinking I’m getting pregnancy symptoms but it’s in my head I hope. Thoughts ??? Also, I just went to the obgyn 7 days after sex to schedule when I get my bc implant. And the test was negative. Chances of being pregnant // when I should test?? I’m only 16 and scared.