Scared

Well I'm 17. I'll be 18 in April and well I had sex with my boyfriend on the 28th of this past month. No protection and not after pill. And then a couple days later we had sex again without any protection.I got my period on the 7th of this last month. It's been about 9 days since I was suppose to get my period. My boyfriend doesn't want a kid right since we are both graduating this year. I took a pregnancy test and it read Negative. I've been feeling dizzy, moody, tired a lot more, and I've been eating more. I have a appointment with the doctors on Friday to take a pregnancy test again. What should I do? My periods are regular and this has never happened before.