Dear Toni,
Hi! As a preschool teacher, I am pretty confident in assuring you that your daughter is just exhibiting this behavior for your benefit and the attention you admit that she receives.
Ask her teacher and/or director and I am sure that they will tell you that once she gets in the door, the tears are over, and it is all fun for the most part. Developing relationships with new children and adults is so important. I had a son who did something similar when he was in preschool, always crying at drop-off. He got over it, and by the end of the year, cried at pick up, not wanting to leave school!
It is normal for a child at 3 to begin to question what mommy is doing during the time apart, but that is because they worry that either 1) you are too lonely without them (after all, they are the ones we spend all our time with, aren't they? and they are the center of our world, right?) or 2)that you are having fun without them. Sometimes just telling a child that you have "work" to do, and that their "job" is to go to school will ease the anxiety.
From your third paragraph, it sounds like she is adjusting and beginning to open up at school. Something that may help with her interest in preschool is to have a few playdates with the school friends, so that she knows that they aren't only friends that she sees when you leave her. This may help you develop some new relationships, too - some of my best friends are parents of my children's friends.
Love and kiss her, but keep on trying!
R.