I got my period on January 3rd 2012. I had unprotected sex on January 5th 2012. I got what appears to be my period again on January 29. Doesthismean I'm not pregnant?

There will be no way to know until your next period is due.

You are trying for a baby?

No it means that you may not be.

If it a full period, not just spotting, will it last the full time.

And of course a pregnancy test in two weeks to confirm for sure.