Should I take a test?

So I finished my period on 4-6 so I don’t think its possible for me to be pregnant but I’ve been having a little nausea and back pain last week and today. Is there any chance? I’ve been doing Herbalife so I was wondering if maybe that’s making me nauseated but my husband said no cause the nausea just started. Should I even bother testing? Also I’ve been having medium to heavy creamy CM

Help?