five year old problems

I have a five year old daughter and her father and I have been seperated over a year now.  I am currently living with my boyfriend whom she loves, but she has been acting out really bad lately.  I just recently found out I am pregnant.  My daughter loves the idea!!
The thing is, she has been acting out more and more lately.  I know that I need to spend more one on one time with her, but most of the time I can't seem to find any extra time to spend with her.  If I am not tired as ever with this pregnancy, its something else.  
She has been acting up in school, around the house, and completely defies me.  I just don't know what else to do.  I try not to lose my temper, and feel REALLY bad when I do, but can't seem to help it when she starts with her attitudes and whining.  WHAT do I do?  I know this doesn't seem that big of a deal, but she has always been a really great child, until recently that is!!  Please help me come up with some ideas before I go crazy!

[LAYNA]

MY SON DID THAT WHEN I WAS PREGNANT TOO! I HAD TO REASSURE HIM THAT I WOULD ALWAYS LOVE HIM NO MATTER WHAT AND I ALSO TOLD HIM THAT IF HE EVER FELT LIKE WE WERN'T PATING ENOUGH ATTENTION TO HIM AFTER THE BAY COMES TO PLEASE LET US KNOW.  WE ALSO TOLD HIM THAT WE WOULD NEED HIS HELP TAKING CARE OF THE BABY AND THAT WE COULDN'T DO IT WITHOUT HIM AND THAT WE NEED HIM TO SET A GOOD EXAMPLE FOR THE BABY CAUSE HE'LL BE TEACH HER EVERYTHING INCLUDING GOOD BEHAVIOR.  AFTER THE BABY ALL WENT WELL BUT THE WHINING CONTINUED.  WE TOLD HIM THAT SINCE HE WAS SO GOOD AT WHINING CAUSE HE DID IT SO OFTEN THAT WE MAKE HIM COUNT TO TEN AND SAY HIS ABC'S EVERYTIME HE WHINED SO HE WOULD GET BETTER AT THAT TOO!  HE HATES IT!!  BUT IT'S WORKING!!  YOUR DAUGHTER IS A YEAR OLD YOU MAY TRY A HIGHER NUMBER OR SOMETHING ELSE EDUCATIONAL. GOOD LUCK