Help please

I called my dr yesterday bc I was like 5 days late but I was still getting BfN well she said she would see if the dr would give me a blood test well about 10 last night I went to the bathroom and I was like well I guess I started bc there was some blood on my underwear not a whole lot just size of like a 50 cent piece well this what it done though the night  could I still be preg. Or is this my period