I'm Worried

I found out on the first day of my missed period. I took an hpt and it was a BFP. I went to the doctor to confirm. She said it took their test a minute, but it came back positive. The blood test showed 22 HCG. If I'm not mistaken, this is really really low. She said I'm between 3-4 weeks.

Ever since then, I've been having consistent cramping. Mild. Nothing too painful. No bleeding.

But I also don't really have any pregnancy symptoms like I've had in the past at this stage.

I took another test today and it says negative.

I'm very worried and would like some insight, anything anyone could possibly say to make me feel better, or accept the impending doom that's coming. I don't know what to expect.

I go back to the doctor Monday.