38 weeks!!

Is nausea and vomiting a sign of labor? I've been throwing up everything I eat these past few days. After I throw up I have bad acid reflux. No I haven't been around anyone that has been sick. I also have diarrhea but today I've been constipated. Also Is being extra moody/irritable a sign? I haven't been like this my whole pregnancy til now. I'm a ftm and I don't know what's going on with me. Please help!