A little guidance needed:-\

So I had sex with my bf the 12-16 th of Dec. While I was on my period but my period was short futon Friday at 3 pm when it started to spotting on the 15th and than we did it again the 22-23 rd. I'm nausea, dizzy, light headed, cramping like pains but no period. Have threw up a couple times but not much. And I have the feeling that I'm pregnant. I've taken three tests, one positive but faintly,one negative and one that I took never registered but was taken. I'm nervous that if I go to the doctor it will be negative. I have not been sick or around suck ppl, this has been going on since at least the 18th.