I didn't take my DH's last name. I wanted to keep my maiden name for career and family reasons. I actually love my maiden name. Our kids have DH's last name. Ideally the kids could've had my maiden name as a middle name but it doesn't work well. I have been called Mrs. DH's Last Name on occasion and it doesn't bother me. We haven't encountered any issues with me having a different last name. The only time it threw me off was when my first child was born, and at the hospital he was known as Baby My Last Name. All of his records and ID tags had my name on them. I told the nurses that wasn't his last name but they informed me that for their purposes, the baby's name follows the mom's name. My MIL flipped when she saw my last name on everything at the hospital until we explained the situation and reassured her that the baby would have DH's last name.
OP - you don't have to change your name right away. You can do it at any time, so don't feel like you have to make this decision by your wedding date. I know a few women who didn't change their last names until they had kids.