Weight gain nausea vomiting hot flashes and abdominal pain

And your question is should you call your doctor for a visit? Yes.
There are many possible reasons for your symptoms (including pregnancy).

While quite rare, pregnancy does happen outside of a uterus. Certainly, as joy said, there can be several reasons for what you are feeling... changes in hormones can be part of the issue. It would be wise to see your doctor to determine a cause.

I know a woman who had her uterus removed, except for a tiny bit to make a flap over the cervix. She delivered a healthy baby inside that tiny bit of uterus, which ballooned up to normal size.