Could I still be pregnant?

I missed my period. I took a digital test the day I missed it and it was positive. I tried not to get too excited cause last time I took a different brand First Response Gold a month before and got a positive and went to do a blood test and it was negative. I've been peeing a ton too recently so I thought I definitely could've been. I went in that same day I took the digital and the HCG was below 2.4 again so apparently I'm not pregnant. Tomorrow will be 8 days since my missed period. Anyone experience this? Is there a chance I still could be?