Nope I don't regret it at all. And as a pp said, I think about surprisingly little these day (my kids are 4.)
Just this morning I had someone tell me that my daughter is the "spitting image" of me. Which is silly, but it's still nice to hear and doesn't leave me feeling as conflicted as those comments did in the beginning.
There is absolutely zero doubt about me being the mother of these kids. None. It's kind of amazing how unequivocal that is and how deep that feeling goes. I have no insecurity about that, no issues with bonding, no significant fears about their thoughts later in life (we talk about the concept of donor egg with them already), etc... It's been much easier/simpler in practice, especially as they get older, than it was in contemplating it.
Now, that is NOT to say that the often talked about, mythical "maternal instinct" is quite what everyone says. But that's a much more universal problem than just a donor egg issue.
Good luck OP. Happy to answer any specific questions if you have them. I also highly recommend talking w/ a counselor who specializes in this area. I resisted that, didn't think it was necessary, but it was really quite helpful to get that perspective and thoughtful advice about what to consider in the decision making process.