Possible pregnancy

I have two kids already and have been getting the exact same early pregnancy symptoms that I did with them. My period is a week late roughly, sore boobs, weeing a lot, nauseas, cravings, thick clear sticky discharge, headaches, bloating etc. I also had what I think was implantation spotting and cramping for two days and that would have been around 5 days after we would have had sex. I have done two home pregnancy tests last week so I would have only been 1-2 weeks I think. I remember with my two kids the second line was very faint like these tests were. Although, I had a blood test done on Monday and the results came back negative today. So my question is, could it be possible for the blood test to not show pregnancy yet if I'm too early on? Thank you