THIS! I had a similar statement posed to me, in my early 30's as I was pondering PA or MD... I'm now coming to the end of my 2nd year in medical school and very glad I took the leap.
As for the OP's post... honestly age is just a number at the end of the day. I'm 35 this year, have many friends at school in their late 20's and early 30's... and nothing really separates us except for the few times I am able to lend some life experience to a group-learning scenario, or when I act like a mom and fetch my friends food during long study days (making sure we also have utensils, plates, and of course: napkins!). Most likely, you will be glad you took that side road because it will mostly likely give you some unique perspectives both as a medical student and as a physician. You are not behind - you are bringing a different life perspective to the table. It will be one of your strengths, not weaknesses.
For the specific questions:
Did you feel like you had to give up on a more time-consuming specialty due to starting later - sometimes, but I have fallen in love with family medicine, so at the end of the day it wont be an issue.
How much did starting later affect your personal life - I married my amazing husband before med school started - we've been together over 6 years. As for kids, I know many female doctors who had kids during residency, and if this was something I wanted to do - I believe it would be very possible. I do miss my siblings and seeing their kids grow up more often - but the time we do spend together is of much higher value than it used to be (because my time is so limited at times).
Do you have any regrets about your decision? The only thing I regret is not believing I could do this sooner - and thinking that age is more of an issue than it really is. Yet, due to my age I am able to bring a different perspective to the table, and I believe this will greatly help me as a family doc - and it has helped me as a medical student greatly.
Let me know if you have any other questions. Don't hold yourself back!!
Best of luck to you!!
P.s. read Sheryl Sandberg's "Lean In", it will change your life.