I Had A Tubal Ligation 33 Years Ago. I'm Now

I had a tubal ligation 33 years ago. I'm now 56. Last month I had tender breast and some back discomfort. Then, the nausea started and it's continued. I've been nauseous every day at some point for about a month and a half now. I'm menopausal and had my last period in April 2014. I didn't think it was possible to get pregnant, but the nausea reminded me of my first pregnancy. So, I took a home pregnancy test and it came back negative, but the indicator line showed up faintly. Is it possible that I can be pregnant? I also recently lost about 25lbs.