13 weeks sudden nausea and cramps

Edith
I suddenly started feeling really nauseated and am having backache, cramps and sudden loss of appetite. I don't know if it's something I ate that upset my stomach. Yesterday I was SUPER gassy. I'm feeling a bit better today but just really tired. Should I call the doctor or just wait to see if I feel better tomorrow? Just looking for some reassurance that I'm OK. I was feeling really well and all of a sudden started feeling bad..