Negative blood test, but still no period.

Hi all. I’m 4 days late, which is very rare for me. I have been testing negative and yesterday (at 3 days late) I went in for a blood test, which came back negative. I have been nauseous for 3-4 days. Not throwing up, just nauseated and peeing all the time. I’m trying to convince myself that my period is coming and just weird this month, but we just started trying and it seems odd that my period is so late when it never is. Anyone take a blood test and end up pregnant? Or anyone experience this and just get a really late period?