Someone like me

I am 5dpo and I am having the worst heartburn and Nausea possible. I rarely get heartburn and almost anything spicy and sometimes not spicy I get it ugh . I used to eat the hottest green chile ever and I can't and my lower back is killing me could this I am pregnant one can only hope ? Has anyone else experiencing this ? I have been taking my temp every morning and it goes up and then it goes down . So I don't know if anyone could answe this . My AF isn't due til the 21st so I know it's still early to test and I don't wanna get a bfn