When should I start to worry

This has been going on for maybe 2 weeks now. I’ve been getting nauseous throughout the day. And then I barely eat. Maybe once a day because I’m not even hungry. When I do eat I get fill very very fast. I do have IBS but I’ve never felt this way before. How long should I wait before I see someone. Or any doctors or nurses on here that have advice or ideas to what could be causing this. I get my period in 6 days, but again this has been going on for 2 weeks. I’ve never had this issue before.