Not realy sure what to do..?

Okay, There is a chance I could be pregnant. I had a couple symptoms(loss of appetite, Very tender and , being a bit 'backed up' sorry... tmi.) But the weird thing was that was all right before and during the time I was waiting on my period. (and I never have any pre-period symptoms aside from cramps) And another thing, On the day that I knew I was going to be late if I didnt start I had 1 day of normal bleeding. just one day though. any help will be awesome.. thanks