Pain 😕

Hi everyone,

I need your advice. I was laying on the couch and started to feel pain on the right side of my stomach. Got up, felt fine. As I began to get ready for bed the pain came back and much more painful. At the moment I am laying down and the pain is unbearable. It really feels like someone is stabbing me (I'm not sure how else to explain it). I am late on my period by a week and I took a test that came out negative

What can it be or how can I get rid of it? Any advice?