lack of period symptoms and constipation anybody know what's going on?

so my period is due within the next two days but I haven't had any symptoms of my period no back pain no cramping I'm incredibly tired all the time now I am incredibly constipated off and on I feel slightly sick in the mornings and at night wondering if I might be pregnant but still might be too soon to tell anybody don't have something like this happen to them and what do you think?