8 days late

Tiffany

I’m 8 days late, which NEVER happens unless I’m pregnant. Ok my 5th day late I took a home pregnancy test which came back negative than I went to the doctors they took out blood and they said it was negative. My sister told me they should have checked the levels and than told me to come back in a few days to check it again to see if it was any higher, but they didn’t mention anything about that. Is that true? Could I possibly still be pregnant? Can 5 days late still be a little early to detect even through blood? I’m freaking out because I take medication and I don’t want to continue taking things if I’m pregnant and possible harm my baby. It’s just so weird to me that I’m 8 days late and nothing show up. Advice please