Help please !

As
I took a first response test yesterday around 11am and it came back with a faint positive so after doing a happy dance I ran out and bought some more tests of different brands and another first response. These all came back negative then this morning with fmu I took another first response test and it looks negative to me. There is possibly a faint line but I think that's just more of me putting it in my head. I'm only about 8 or 9dpo so do you think my hormones are just very low at this point and aren't being picked up? Do you think there is still a chance I'm pregnant? I'm just confused since yesterday I got a positive. Just looking for other opinions. Thank you!