Help might be pregnant

Ok I'm new here, but here's my story I had a still born last March and now I think I might be pregnant my period was only 4 days last month and it's not due until next week! I had the gastric sleeve done but I notice I have gain weight I. My stomach where it looks like a basketball it I had the cramps in the lower part of my stomach my boobs are sensitive as well as heartburn and nausea. So if anyone can help let me know thanks