Has anyone had this 6 DPO?

When I woke up this morning I felt fine. When I got to work I was filling up my mop bucket (I'm a housekeeper) and felt like I had to burp. When I did, chunks of my breakfast came up and so did acid. I have only had that happen to me once, and that was when I was 5 week a pregnant. After that I got real shaky, dizzy, nauseous and very sweaty. I have other symptoms too such as a constant headache, I'm exhausted all the time, nausea off and on, and my boobs are a little sore, not much though. I don't want to link this to pregnancy because I'm sure I'm not since all my tests come back negative, and I'm only 6 DPO. Is it possible to have all these symptoms when implantation probably hasn't even occured? I just don't know what all this means. I'm trying not to get my hopes up, but it's hard. Any input?