For reassurance, I've personally gone mad with symptoms like this. However, those are definitely common early pregnancy symptoms, especially constipation. Having your period a week early isn't totally out of the norm, but it could mean that your cycle off.
If I were you I would take a home pregnancy test now, just to confirm that that period was indeed a period and not implantation bleeding.
If it comes back negative, then your symptoms are probably related to ovulation hormones since your period was two weeks ago (meaning, if it was a true period, you should be ovulating soon here).