My period started January 28, 2014. Then it ended the first of February, 15 days later on February 17th I had a really light period where I didn't even need to use anything it lasted 5 days I think it could be implantationbleeding maybe. Now its march 13th. I have sore nipples, I'm craving pickles and I hate pickles, I have to pee all the time and I'm nauseous all the time. Could I be pregnant and if so could I take a pregnancy test today?

Symptoms are meaningless.
Any woman who has sex can be pregnant.
Yes, you should try a HPT now. And please, if you are playing Russian roulette, stop sex now and get some real BC.

Since your last period was off from its norm, and you are having some possible pregnancy symptoms, try a test now. If negative, see what happens when you would expect a period for March.

You may and can do a test now. It may be too early, so if it is Neg, wait two week and test again if not period.